Ichigo USMLE Med Diagnosis P3

1) A 63-year-old white female presents with a thyroid nodule. She denies any weight loss, change in appetite, diarrhea, heat or cold intolerance, menstrual irregularities, hoarseness and dyspnea. Her past medical history is unremarkable. There is no family history of thyroid cancer. She does not take any medications. Physical examination shows a 4-5 cm, fixed, hard, and non-tender thyroid nodule. There is cervical lymphadenopathy. Her serum TSH level is normal. Fine needle aspiration (FNA) of the thyroid shows malignant cells. Which of the following is the most likely expected pathology on FNA?

2) A 36-year-old female presents with headaches and visual problems. She also complains of palpitations, heat intolerance and weight loss. Her past medical history is unremarkable. She is currently on no medications. Her blood pressure is 130/60 mmHg, heart rate is 100/min and regular, and weight is 152 lb (weight one year ago was 170 lb). Physical examination reveals a symmetrically enlarged thyroid gland without any tenderness. Auscultation of the chest reveals tachycardia. She has bitemporal hemianopsia on confrontation. The rest of the physical examination is unremarkable. Her lab investigations show: Serum T3 222 ng/mL, Serum T4 13.9 mcg/dL, Serum TSH 7.9 IU/mL, Alpha subunit level elevated. Which of the following is the most likely diagnosis?

3) A 35-year-old male presents with complaints of weakness and fatigue of one year's duration. He is anorexic and has lost interest in all his activities. He also complains of cold intolerance and constipation. His blood pressure is 98/72 mmHg, temperature is 37.1°C (99°F), respirations are 14/min, and pulse is 50/min. His skin is dry and rough, nails are brittle, and hair is thin. There is no hyperpigmentation of the skin. Delayed deep tendon reflexes are noted on neurological examination. Lab studies show: Hemoglobin 10.2 g/dL, WBC count 5,000/micro-L, Neutrophils 45%, Monocytes 5%, Eosinophils 10%, Basophils 1%, Lymphocytes 40%, Serum sodium 135 mEq/L, Serum potassium 4.0 mEq/L. Which of the following is most consistent with this patient's findings?

4) A 60-year-old male is admitted to the hospital because of right lower lobe pneumonia. His medical history is significant for hypertension, diabetes mellitus, severe degenerative disease of the spine, and longstanding lower back pain. He is a chronic smoker with a 40-pack year smoking history. During his hospitalization, the laboratory report shows decreased serum calcium levels and increased phosphate levels. Further evaluation reveals increased serum intact parathyroid hormone levels. Which of the following medical conditions is most likely responsible for this patient's abnormal lab findings?

5) A 43-year-old female presents to the physician's office with muscle cramps, polydipsia and polyuria. She has no other medical problems, and does not take any medications. She does not use tobacco, alcohol or drugs. Her father died from alcoholic liver disease at age 50. Her pulse is 75/min, respirations are 13/min, blood pressure is 160/100 mmHg, and temperature is 37°C (98.6°F). Laboratory studies show: Blood glucose 115 mg/dL, Serum sodium 142 mEq/L, Serum potassium 2.7 mEq/L. Plasma renin activity is low. What is the most likely diagnosis?

6) A 30-year-old Hispanic male presents to the office with complaints of palpitations, tremor, nervousness and headache. His past history is insignificant. His mother has type 2 diabetes, which is well-controlled with medications. His temperature is 37.0°C (98.6°F), pulse is 100/min, blood pressure is 150/80 mmHg, and respirations are 16/min. He appears anxious, sweaty and shaky. His neurological examination is non-focal, and examination of other systems is unremarkable. His fingerstick blood glucose level is 38 mg/dL. Intravenous administration of a bolus of 50% dextrose leads to the improvement of his symptoms. He is then subjected to supervise prolonged fasting. After an overnight fast, laboratory studies reveal: Blood glucose 40 mg/dl, Serum insulin 15 microU/L (normal value is < 6 microU/L with hypoglycemia), Serum pro-insulin 9 microU/L (normal value is < 20% of total immunoreactive insulin), C-peptide level 0.8 nmol/L (normal value is less than 0.2 nmol/L), Sulfonylurea Negative, IGF-II Negative. Based on the above information, what is the most likely cause of this patient's hypoglycemia?

7) A 35-year-old male presents to the family physician for bilateral gynecomastia. He observed a progressive increase in his breast size starting 6 months ago. He is sexually active and denies any drug use. Physical examination reveals bilateral gynecomastia and tenderness. The genito-urinary examination shows a 1 cm nodule in the right testis. Otherwise, the examination is within normal limits. The laboratory report shows: LH 3 U/L, FSH 2 U/L, testosterone 270 ng/dL (Normal 3-10 ng/dL), estradiol 115 pg/mL (Normal 20-60 pg/mL), beta HCG undetectable, AFP undetectable. Which is the most likely diagnosis?

8) A 39-year-old woman comes to the physician because of a "pins and needles" sensation around her mouth for the last 2-3 weeks. She gets similar sensations in her feet sometimes, along with muscle cramps, especially at the end of the day. She has no similar episodes in the past and has always been healthy. She works as a waitress and has "clean habits." Her family history is not significant. She is currently not taking any medications, and is allergic to penicillin. Her vital signs are normal. Examination is unremarkable. The patient's labs reveal: CBC: Hb 12.4 g/dl, WBC 6,000/cmm. Serum: Serum Na 140 mEq/L, Serum K 4.0 mEq/L, Chloride 100 mEq/L, Bicarbonate 24 mEq/L, BUN 10 mg/dl, Serum creatinine 0.8 mg/dl, Glucose 100 mg/dl, Calcium 6.5 mg/dl, Phosphorus, inorganic 5.8 mg/dl. Protein: Total 7.0 g/dl, Albumin 3.8 g/dl, Globulins 3.0 g/dl. Which of the following is the most likely cause of her condition?

9) A 56-year-old male presents in the emergency department with severe nausea, vomiting, polyuria, polydipsia, and constipation. His past medical history is significant for hypertension and type 2 diabetes mellitus. His home medications include metformin, atenolol, and hydrochlorothiazide. He has a 26-pack-year history of smoking. He drinks alcohol occasionally. He denies the use of recreational drugs. His father also has diabetes mellitus type 2. His blood pressure is 110/70 mmHg, pulse is 102/min, temperature is 36.7°C (98°F) and respirations are 16/min. His mucus membranes are dry. His lung examination reveals decreased breath sounds over the right base. The rest of the physical examination is unremarkable. The patient is subsequently admitted. Laboratory studies (obtained in the emergency department) are as follows: Serum calcium 14.8 mg/dl, Albumin 4.0 g/dl, PTH 9 pg/ml (normal 10-60 pg/ml), Serum creatinine 1.9 mg/dl, BUN 54 mg/dl, Blood glucose 180 mg/dl, 25-hydroxyvitamin D 30 ng/ml (normal 20 to 60 ng/ml), 1,25-dihydroxyvitamin D 30 pg/ml (normal 15 to 65 pg/ml). What is the most likely cause of this patient's hypercalcemia?

10) A 63-year-old otherwise healthy male presents with a thyroid nodule. He denies any symptoms of anxiety, heat or cold intolerance, and recent changes in appetite or weight. He has hypertension, which is being treated with a beta-blocker. He does not have any other medical problems. He denies any family history of thyroid disease. His pulse is 79/min and blood pressure is 130/76 mmHg. Neck examination shows a hard, fixed, non-tender, 4 cm thyroid nodule in the right thyroid lobe. His serum TSH level is normal. Fine needle aspiration biopsy (FNAB) shows follicular cells. Follicular carcinoma is suspected. Which of the following is necessary to make a diagnosis of follicular thyroid cancer?

11) A 38-year-old Caucasian female presents to the office complaining of lethargy, weight gain and fatigue. She denies headaches, pruritus or urine discoloration. She just gave birth 2 months ago via vaginal delivery; her baby is in good health and receives formula nutrition. Her delivery was complicated by vaginal bleeding that required blood transfusion, and postpartum endometritis that rapidly responded to antibiotics. She has not had any menstrual periods following delivery. Physical examination shows sparse pubic hair, dry skin and delayed tendon reflexes. Urinalysis shows no glucose or ketones. Which of the following is most likely to be responsible for this patient's condition?

12) A 56-year-old woman presents to the clinic with a 7-month history of headache and visual disturbance. Her past medical history is unremarkable. She is currently not taking any medications. She admits to smoking a pack of cigarettes daily for the last 15-years, and does not drink. On visual field examination, there is a small field defect noted in both eyes. MRI scan shows a pituitary tumor. Which of the following is the most common type of pituitary tumor?

13) A 65-year-old Hispanic male comes to the office for a routine medical check-up. He has a history of diabetes for the past twenty years, and hypertension for the past ten years. His daily medications include insulin and ramipril. He was diagnosed with nonproliferative diabetic retinopathy at his last ophthalmologic visit. Reports from his previous laboratory studies show microalbuminuria. A detailed neurological examination is performed to check for any neuropathy. Which of the following is the most common type of neuropathy found in diabetics?

14) A 65-year-old man presents with a 1-day history of hematuria and sharp flank pain (rated 10 of 10) radiating toward the groin on the right side. Past medical history is significant for three prior episodes of nephrolithiasis over the past 5 years, all of which presented with a similar clinical picture. He is not taking any medication. There is no family history of renal calculi, renal disease, or endocrine disorders. His temperature is 36.9°C (98.5°F), heart rate is 125/min, and blood pressure is 132/86 mmHg. He is in obvious distress and cannot sit still on the bed. Physical examination is significant for a soft, nontender abdomen and extreme costovertebral angle tenderness on the right. Laboratory values show: Na+: 142 mEq/L, K+: 4.8 mEq/L , Cl−: 104 mEq/L, HCO −: 24 mEq/L , Ca2+: 11.0 mg/dL , PO4: 1.4 mg/dL , Mg2+: 2.0 mg/dL , Blood urea nitrogen: 12 mg/dL, Creatinine: 1.0 mg/dL, Glucose: 118 mg/dL, Intact parathyroid hormone: 300 pg/mL. Which of the following is the most likely diagnosis?

15) A 90-year-old male complains of hip and back pain. He has also developed headaches, hearing loss, and tinnitus. On physical examination the skull appears enlarged, with prominent superficial veins. There is marked kyphosis, and the bones of the leg appear deformed. Serum alkaline phosphatase is elevated. Calcium and phosphorus levels are normal. Skull x-ray shows sharply demarcated lucencies in the frontal, parietal, and occipital bones. X-rays of the hip show thickening of the pelvic brim. Which of the following is the most likely diagnosis?

16) A 35-year-old white male presents with fatigue, decreased appetite, weight gain, constipation and cold intolerance. He cannot recall any stressful event. He does not take any medications. He is a non-smoker and non-alcoholic. His pulse is 47/min and blood pressure is 145/91 mmHg. Physical examination reveals cool, pale skin, coarse hair, and brittle nails. There is delayed relaxation of deep tendon reflexes. The thyroid gland is normal on palpation. Laboratory studies reveal increased serum free T3 and T4 levels, and normal serum TSH level. Which of the following is the most likely diagnosis?

17) A 65-year-old diabetic male with acute myocardial infarction complicated by cardiogenic shock is admitted in the coronary care unit. His hospital course was complicated by acute renal failure and lower GI bleeding from anticoagulation therapy. His thyroid hormone studies are abnormal. He does not have any previous history of thyroid disease. Physical examination of the thyroid gland is normal. Labs show: Triiodothyronine (T3), serum 1.4 nmol/L (normal 1.8-29 nmol/L), Thyroxine (T 4), serum 6.0 micro-g/dL (normal 5-12 micro-g/dL), Thyroid-stimulating hormone, serum 2.0 micro-U/mL. Which of the following is the most likely diagnosis?

18) A 45-year-old male presents to your office because his "hands are getting thick and swollen." He is also having difficulty with wearing shoes because his feet have become large. His blood pressure is 150/90 mmHg. On examination, he has enlarged, swollen hands and feet. He has coarse facial features, with prominent frontal bones and jaws. While you are discussing the most likely diagnosis, he appears worried and asks about the complications and risk of death associated with his condition. What is the most common cause of death in patients with this condition?

19) A 17-year-old girl presents to the clinic because she has not yet menstruated and does not have significant breast development. Family history is significant only for some cousins who are color blind. The patient denies ethanol, tobacco, and illicit drug use and sexual activity. Physical examination reveals a normal-appearing girl in no acute distress with minimal breast development and a lack of pubic hair. She is 168 cm (5'6") tall and weighs 61.2 kg (135 lb). Cardiac examination reveals no murmurs, rubs, or gallops, with point of maximal impulse at the left mid-clavicular line between the third and fourth intercostal space. Gynecologic examination reveals a vagina without rugae and a cervix that is easily visualized. There is no discharge. A urine test is negative for β-human chorionic gonadotropin. Which of the following is the most likely diagnosis?

20) A 26-year-old man presents with increased thirst, urinary frequency, and nocturia over the past several months. Physical examination is unremarkable. Twenty-four-hour urine osmolarity is < 300 mOsm/L. A fluid deprivation test does not result in an increased urine osmolarity. Administration of 0.03 μg/kg of desmopressin results in a urine osmolarity of 450 mOsm/L after 2 hours. Which of the following is the most likely diagnosis?

21) A 48-year-old woman presents to her primary care physician because of 2 weeks of neck pain. The pain is constant and sharp (rated at 10 of 10) and is felt in the anterior portion of her neck. She also notes several weeks of loose stools and fatigue. Past medical history is significant for a viral upper respiratory infection about 1 month ago. She has a temperature of 37.9°C (100.2°F), heart rate of 96/min, and blood pressure of 136/82 mmHg. On neck examination there is diffuse enlargement of the thyroid and it is exquisitely tender to even mild palpation. Laboratory tests show a total tri-iodothyronine level of 280 ng/dL, total thyroxine of 25 μg/dL, and thyroid-stimulating hormone of 2 μU/mL (normal: 0.4–4 μU/L).Which of the following is the most likely diagnosis?

22) A 74-year-old woman is brought to the emergency department by her daughter. The daughter states that her mother lives alone and has no significant medical problems. She says that she last saw her mother a month prior, before she left on an extended business trip. When she returned, she found her mother appeared restless and very nervous. She also appeared to have lost a noticeable amount of weight. The patient told her daughter that she had been having increased frequency of bowel movements, and felt like her heart was beating fast and funny, and that she felt like she might be coming down with a cold. Initial evaluation in the emergency department reveals sinus tachycardia and a painful, enlarged thyroid. Which of the following is the most likely etiology of her symptoms?

23) A 32-year-old woman undergoes a cesarean section because of failure of labor to progress, and delivers a healthy baby boy. The procedure is complicated by significant intraoperative blood loss and hypotension, but the patient is successfully resuscitated. Postoperatively she experiences dull, aching, non-localized abdominal pain and nausea, but denies headache, visual changes, or abnormal edema. On postoperative day three she is passing flatus and remains afebrile, but becomes hypotensive to 90–100 mm Hg systolic and 40–50 mm Hg diastolic. She has not begun lactating despite her attempts to breast-feed her infant. Laboratory values indicate that she is hyponatremic and mildly hyperkalemic. Urinalysis and liver enzymes are normal. Which of the following is the most likely cause of her symptoms?

24) A 24-year-old white male presents with a persistent headache for the past few months. The headache has been gradually worsening and not responding to over-the-counter medicines. He reports trouble with his peripheral vision which he noticed while driving. He takes no medications. He denies illicit drug use but has smoked one pack of cigarettes per day since the age of 18. Past history is significant for an episode of kidney stones last year. He tells you no treatment was needed as he passed the stones, and he was told to increase his fluid intake. Family history is positive for diabetes in his mother and a brother (age 20) who has had kidney stones from too much calcium and a “low sugar problem.” His father died of some type of tumor at age 40. Physical examination reveals a deficit in temporal fields of vision and a few subcutaneous lipomas. Laboratory results are as follows: Calcium: 11.8 mg/dL (normal 8.5-10.5), Cr: 1.1 mg/dL, Bun: 17 mg/dL, Glucose: 70 mg/dL, Prolactin: 220 μg/L (normal 0-20), Intact parathormone: 90 pg/mL (normal 8-51). You suspect a pituitary tumor and order an MRI which reveals a 0.7 cm pituitary mass. Based on this patient’s presentation, which of the following is the most probable diagnosis?

25) A 26-year-old man with a history of kidney stones presents with 1 week of severe burning epigastric pain. He also notes several days of diarrhea and nausea but denies emesis or fever. His family history is remarkable for a paternal uncle with pancreatic cancer. His temperature is 37°C (98.6°F), heart rate is 88/min, respiratory rate is 16/min, and blood pressure is 125/85 mm Hg. Abdominal examination is significant for tenderness in the mid-epigastrium. Upper endoscopy reveals a 1-cm ulceration in the first part of the duodenum. This is the third episode of confirmed peptic ulcers in this patient. Laboratory studies show: Na+: 140 mEq/L, K+: 4.9 mEq/L , Cl−: 105 mEq/L, HCO −: 25 mEq/L, Ca2+: 12.0 mg/dL, PO4: 1.4 mg/dL, Mg2+: 2.0 mg/dL, Blood urea nitrogen: 10 mg/dL Creatinine: 1.0 mg/dL , Glucose: 87 mg/dL. Which of the following is most likely to be found in this patient?

26) A 52-year-old man presents to the primary care clinic for the first time. He states that he has been in good health throughout his life and takes no medications. He was once athletic but has noted a dramatic decrease in his muscle strength and exercise tolerance over the past year. On examination the patient is moderately hypertensive, with a tanned, round, plethoric face; large supraclavicular fat pads; and significant truncal obesity. He has no focal cardiovascular, pulmonary, or neurologic findings. His fasting blood sugar is 200 mg/dL. Which of the following is the most common etiology of this condition?

27) A 3-year-old girl is brought to the pediatrician’s office because of an abdominal mass. Physical examination reveals short stature, coarse facial features, a protruding tongue, and an easily reducible umbilical hernia. The girl has difficulty walking and knows six words, although she is unable to form a sentence. Her mother reports no health problems and an uncomplicated pregnancy. What is the most likely cause of the patient’s condition?

28) A moderately overweight 34-year-old woman presents to the emergency department with excessive sweating, flushing, tachycardia, and nervousness. Presuming that she might be suffering from thyrotoxicosis, the physician checks her blood levels of thyroid hormones, and finds that her free thyroxine and triiodothyronine levels are elevated, while her thyroid-stimulating hormone is decreased. Her radioactive iodine uptake test shows a complete absence of iodine uptake. Which of the following is the most likely diagnosis?

29) A 28-year-old Caucasian male presents to the emergency department complaining of neck pain for the past two days. He states that a chicken bone scratched the back of his throat a week ago. Two weeks ago, he was in Arizona visiting his friends. He is otherwise healthy and has never been hospitalized. His temperature is 39°C (102.2°F), blood pressure is 125/85 mmHg, and heart rate is 120/min. On examination, he refuses to fully open his mouth. Neck movements, especially neck extension, are restricted secondary to pain. Which of the following is the most likely diagnosis?

30) A 7-year-old boy with a 6-day history of nasal discharge presents with a swollen and painful left eye. His blood pressure is 100/70 mmHg, pulse is 92/min, respirations are 18/min, and temperature is 39.4°C (103°F). Examination of the left eye reveals swollen and erythematous eyelids, mild protrusion of the eyeball, and pain with eye movements. The affected eye is tender and his visual acuity is decreased. Funduscopic examination is normal. Which of the following is the most likely diagnosis?

31) A 32-year-old male complains of difficulty hearing in his left ear for the past month. He denies any headaches, fever, chills, weight loss, or ear discharge. He is HIV positive, and is currently being treated with highly active antiretroviral therapy (HAART). He also takes trimethoprim/sulfamethoxazole daily. His most recent CD4 count was 425/mm3. Examination of the affected ear shows a dull, hypomobile tympanic membrane. What is the most likely cause of hearing loss in this patient?

32) A 36-year-old woman presents to your office with complaints of worsening throat pain for the past six days. She also has pain in her ears and neck as well as difficulty swallowing. On examination, she has excessive salivation and difficulty opening her mouth. Her temperature is 39°C (102.2°F), blood pressure is 130/80 mmHg, pulse is 100/min, and respiratory rate is 18/min. Which of the following neck space infections carries the highest risk of mediastinal involvement?

33) A 23-year-old male comes to your office with a 10-day history of severe headaches. He states that they are sharp in character and are mostly right-sided involving the frontal area. The headaches interfere with his sleep, and he also complains of double vision, nausea, and malaise. His blood pressure is 120/80 mmHg, pulse is 103/min, respirations are 14/min, and temperature is 38.0°C (100.5°F). Examination reveals bilateral periorbital edema. There is subtle right-sided lateral gaze palsy. Which of the following is the most likely diagnosis?

34) A 24-year-old Caucasian female complains of recurrent painful ulcers in her mouth and occasional abdominal pain. She has also unintentionally lost 5 pounds over the last six months. She is not sexually active, and denies use of tobacco, alcohol, or drugs. Past medical history is noncontributory and she takes no regular medications. Her mother suffers from asthma and her father has prostate cancer. She is afebrile with a blood pressure of 118/69 mmHg and pulse of 71/min. Physical examination reveals mild abdominal tenderness primarily in the lower abdomen without guarding or rebound. Several shallow ulcers are seen on the buccal mucosa. A biopsy of one of the ulcers demonstrates granulomatous inflammation. Her hematocrit is 42%. Which of the following is the most likely cause of this patient's complaints?

35) A 70-year-old man comes to your office with complaints of difficulty hearing. His wife says that he has been raising the television volume much louder recently. The patient claims that he can hear well when he talks to his family members at home, but he has significant difficulty hearing in restaurants or during other family gatherings, which is why he prefers to stay at home most of the time. He worked in a shipbuilding yard for 30 years, and retired five years ago. He has no history of significant noise exposure. What is the most likely diagnosis?

36) A 12-year-old girl comes to the office complaining of a small amount of left-sided ear discharge that has persisted for the last three weeks. She has completed two courses of antibiotics that were prescribed during her previous visits. She also complains of hearing loss on the left side. On examination, she is afebrile. Otoscopy reveals an intact left tympanic membrane with peripheral granulation and some skin debris. The patient should be evaluated for which of the following?

37) A 33-year-old Caucasian female has suffered from recurrent episodes of dizziness over the last six months. She describes the episodes as a sensation of severe spinning that last one to two hours and are accompanied by intense nausea. She also feels unsteady during the episode, and has to lie down with her eyes closed for relief. There is no particular factor that precipitates the episodes. She denies any headaches, but complains of fullness in her right ear. She has no ear pain or ear discharge. She has used some over-the-counter ear drops with minimal relief of the fullness sensation. She prefers holding her cell phone on the left side. Which of the following is the most likely cause of this patient's condition?

38) A 6-year-old boy is brought to the office by his mother due to a decreased appetite and irritability for the past three days. He also had an episode of diarrhea yesterday. Lately, he has been sitting close to the television with the volume turned up very loudly. His temperature is 38.1°C (100.5°F), blood pressure is 110/60 mmHg, and heart rate is 110/min. On examination, there is left-sided yellowish ear discharge. His nasal mucosa appears boggy and postnasal drip is present. What is the most likely diagnosis?

39) A 28-year-old African American female complains of recurrent nasal discharge and increasing nasal congestion. She has a constant sensation of dripping in the back of her throat, and states that food has tasted bland to her recently. She is known to have sickle cell trait. She came to the emergency department for severe wheezing after taking naproxen for menstrual cramping one year ago. She has no history of head trauma. She does not smoke cigarettes, but she admits to smoking marijuana occasionally. Which of the following is the most likely diagnosis?

40) A 26-year-old man comes to your office with a one-week history of right-sided ear pain. The pain often wakes him up at night, and increases in severity when he chews food. He cannot recall any recent episodes of pharyngitis. He denies having any ear discharge, sinus tenderness, or skin rash. He exercises by swimming frequently at a local club. He is sexually active and uses condoms "quite regularly." He lives with his brother, who often comments on his habit of grinding his teeth at night. On examination, his ears are normal with a mild amount of wax. Pain is not elicited by pulling on the pinna. There are no hearing deficits appreciated. Mobility of the tympanic membrane is normal, and the Weber and Rinne test results are within normal limits. What is the most likely diagnosis?

42) A 45-year-old nurse practitioner presents to the emergency department due to painful abdominal cramps and watery diarrhea. She has about 10 to 20 bowel movements a day. She also has nocturnal bowel movements. She has had multiple hospitalizations in the past for similar problems without a definite diagnosis. A lower GI endoscopy during a previous hospitalization showed dark brown discoloration of the colon with lymph follicles shining through as pale patches. Which of the following is the most likely diagnosis?

44) A 65-year-old man comes to the physician's office with a 2-month history of dysphagia. He initially had difficulty swallowing solids, but now this includes liquids. He has occasional heartburn, which usually responds well to antacids. He has lost 20 lbs of weight in the past 2 months. He has a 40 pack- year history of smoking. He has been a chronic alcoholic for 20 years. His temperature is 36.7°C (98°F), blood pressure is 110/80 mmHg, pulse is 66/min, and respirations are 14/min. Physical examination shows no abnormalities. Barium studies show a minimally dilated esophagus with beak-shaped narrowing. Manometry shows increased lower esophageal sphincter tone. Which of the following is the most likely diagnosis?

45) Ms. Lee, a 62-year-old Chinese woman, comes with yellowness in her eyes for the past 6 weeks. She is generally feeling tired, has lost some weight, and occasionally had some nausea. She denies any altered bowel habits. She is a non-smoker but drinks 2-3 beers each night. Her dad is suffering from high cholesterol and also has had stroke. She had a dilatation and curettage for an abnormal pap smear 15 years ago. Her vitals are stable and she is afebrile. She has marked scleral icterus. An abdominal examination reveals normal bowel sounds and no organomegaly. Her stools were occult blood negative. Her liver function tests and enzymes were ordered and the results are: Total protein 6.1 g/dl, Albumin 39 g/dl, AST 67U/L, ALT 52U/L, Alkaline phosphatase 290 U/L, Total bilirubin 96 mg/dl, Direct bilirubin 89 mg/dl, Serum lipase is 46 U/L, Anti-mitochondrial antibodies negative. Which of the following is the most likely cause of these findings?

46) A 64-year-old white male with a history of severe stable angina and peripheral vascular disease undergoes coronary artery bypass surgery. His post-operative course is complicated by hypotension, which is treated successfully; however, a few hours later, he experiences abdominal pain followed by bloody diarrhea. His temperature is 37.8°C (100°F), blood pressure is 110/60 mmHg, pulse is 110/min, and respirations are 20/min. Abdominal examination is benign. Laboratory studies show a WBC count of 15,000/cmm with 7% bands. The lactic acid level is elevated. A CT scan is ordered. Which of the following areas of the colon will most likely show abnormal findings?

47) A 52-year-old man presents to your office after passing a black stool. He also describes occasional abdominal discomfort and nausea but denies hematemesis. He says that food seems to help his abdominal pain, so he eats frequently during the day and keeps some snacks on his night stand. As a consequence, he has gained 5 pounds over the last year. He admits that his diet is lacking in vegetables and fruit. He drinks one to two cans of beer nightly, but does not smoke or use illicit drugs. He says that his father died of colon cancer and his mother died from a stroke. Physical examination reveals a right-sided carotid bruit. The fecal occult blood test is positive. Which of the following is the most likely cause of his condition?

48) A 35-year-old Caucasian female presents to your office with several months history of heartburn. She also describes a periodic 'sticking sensation' in her throat during the meal. Her past medical history is significant for asthma that is controlled with inhaled steroids, and acoustic neuroma that was removed 2 years ago. She does not smoke or consume alcohol. She denies any recreational drug use. She is not allergic to any medications. She works as a secretary at a private firm, and considers her work moderately stressful. Her family history is significant for breast cancer in her mother and prostate cancer in her father. Endoscopic evaluation shows mild hyperemia in the distal esophagus. Esophageal manometry reveals absent peristaltic waves in the lower two-thirds of the esophagus and a significant decrease in lower esophageal sphincter tone. Which of the following is the most likely cause of this patient's complaints?

49) A 42-year-old male comes to the physician's office for evaluation of skin rash and hair loss. He has a long history of Crohn's disease and has had extensive small bowel resection resulting in short bowel syndrome. He is currently receiving total parenteral nutrition. When he does try to eat, he complains that the food does not taste good. His vital signs are stable. Examination shows alopecia and bullous, pustular lesions around the perioral and periorbital areas. Which of the following is the most likely cause of his current symptoms?

50) A 45-year-old Hispanic male comes to the emergency department because of a two-day history of intermittent abdominal pain and bloody diarrhea. He has had four similar episodes in the past year. He is subsequently admitted to the floor. Radiographic and endoscopic evaluations show extensive disease from the terminal ileum to the rectum with multiple ulcerations and pseudopolyps. Biopsy of the lesion shows noncaseating granulomas and crypt abscess. Which of the following is the most characteristic feature which favors the diagnosis of Crohn's disease against that of ulcerative colitis?

53) A 43-year-old man is evaluated for a one-year history of chronic abdominal pain. He describes episodes of epigastric and left upper quadrant pain that last for hours and are not relieved by antacids. Certain foods can precipitate the pain. He also complains of occasional diarrhea. The patient has lost 10 pounds over the last 6 months. Four years ago he was hospitalized for three days with acute abdominal pain. He smokes one pack of cigarettes a day and consumes alcohol regularly. His family history is significant for diabetes mellitus in his mother and prostate cancer in his father. Which of the following is most likely to diagnose this patient's condition?

54) A 50-year-old woman comes to clinic due to several episodes of severe watery diarrhea for the past 15 days. There is 4/10 pain all over her abdomen but she has not noticed any blood in her stools. She has normal diet and has not travelled anywhere recently. She denies any one around her having similar complaints. She also had occasional cramps in her leg muscles and feels dehydrated. She smokes one to two cigarettes a day and drinks socially. Her temperature is 36.8°C (98.1°F), blood pressure is 108/64 mmHg, pulse is 118/min, and respirations are 18/min. On examination her abdomen is slightly tender. Laboratory results are as follows. WBC 5600mm3, Hemoglobin 13.6, Hematocrit: 41%, Platelets 209,000mm3, Sodium 138mEq/L, Potassium: 2.1mEq/L, Bicarbonate: 35mEq/L, Blood urea nitrogen: 16 mg/dl, Creatinine: 0.8 mg/dl, Glucose 106 mg/dl. A CT abdomen is ordered which shows a mass in the head of pancreas. What is the most probable diagnosis?

55) An 83-year-old woman presents with a 1-year history of progressively severe crampy abdominal pain after eating. She has started avoiding food because of the pain. The pain is often associated with bloating, nausea, and occasional diarrhea. She has had a 15 kg (33 lb) weight loss over the past year. Her other medical problems include hypertension, diabetes mellitus-type 2, hypercholesterolemia, peripheral vascular disease, coronary artery disease and myocardial infarction. Social history is not significant. Abdomen is soft, nontender and non-distended. Abdominal x-ray and CT scan are unremarkable. Which of the following is the most likely diagnosis?

56) A 65-year-old woman presents with painless intermittent rectal bleeding. The bleeding is bright red in color. She does not have abdominal pain, nausea, or vomiting. She has a history of hypertension, diabetes mellitus, and hypercholesterolemia. Her temperature is 36.7°C (98° F), blood pressure is 140/80 mmHg, pulse is 80/min, and respirations are 16/min. Physical examination shows a systolic ejection murmur in the right second intercostal space; examination is otherwise unremarkable. Sigmoidoscopy shows no abnormalities. Which of the following is the most likely diagnosis?

57) A 45-year-old white male comes to your office for evaluation of diarrhea of 8-months duration. He says that he has lost almost 15 lbs during the past 8 months. He denies any blood in the stools. 24-hour stool collection reveals fecal fat of 10 gm/day. Stool microscopy reveals no pathogens and no leucocytes. D-xylose test was performed which shows that less than 2 grams of D-xylose is excreted in urine in 5 hours. D-xylose test was re-performed after 4-week treatment with antibiotics but excretion is still less than 2 grams in 5 hours. Based on these findings, what is the most likely diagnosis in this patient?

58) A 27-year-old male presents with a history of intermittent abdominal distention, flatulence and greasy stools. He also complains of fatigue. He has no other medical problems. His family history is unremarkable. He does not use tobacco, alcohol or smoking. His vital signs are within normal limits. Physical examination shows a pruritic, papulovesicular rash over the extensor surfaces of the extremities and over the trunk, scalp and neck. His abdomen is soft, nontender and non-distended. Stool for occult blood testing is negative. Lab studies show: Hemoglobin 10.0 g/L, MCV 75 fl, Platelets 340,000/mm3, Leukocyte count 4,500/mm3, Neutrophils 56%, Eosinophils 1%, Lymphocytes 33%, Monocytes 10%. Which of the following is the most likely diagnosis of his skin condition?

59) A 49-year-old woman presents with a two-week history of lower abdominal pain and severe diarrhea. The stools are watery without blood or mucus. The abdominal pain is mild and unrelated to her stools. She has had recent episodes of flushing. She has not had fever. There is no history of travel. She does not smoke or drink alcohol. Her past surgical history includes a fracture repair of her right leg 3 years ago. Her temperature is 36.6°C (97.8°F), blood pressure is 106/68 mm Hg, pulse is 103/min, and respirations are 20/min. Oxygen saturation is 99% on room air. Physical examination shows facial flushing, a prominent jugular venous pulse and expiratory wheezes. Which of the following is the most likely diagnosis?

60) A 55-year-old male comes to the physician with a history of diarrhea, weight loss, bloating, and excessive flatulence. His symptoms began soon after having "stomach surgery" two years ago. He has a history of gastric ulcers. Physical examination shows scarring associated with past surgery, and abdominal distention with identifiable succussion splash. Laboratory studies show anemia with MCV of 100fl. Which of the following is the most likely diagnosis?

61) A 50-year-old female presents with a 3-year history of abdominal pain and diarrhea. She has not been evaluated by a physician. Recently, her symptoms have been progressively worsening. Endoscopy shows multiple ulcerations of the duodenum and prominent gastric folds. Secretin stimulation test shows increased gastrin secretion. Which of the following is most likely associated with this patient's condition?

62) A 27-year-old Caucasian woman presents with abdominal pain, diarrhea and a 4.5 (2kg) weight loss for the past two months. She describes the abdominal pain as intermittent, moderate-to-severe, and located in the right lower quadrant. Over the past 48 hours, the pain has intensified. Her temperature is 37.6°C (99.6°F), blood pressure is 120/70 mm Hg, pulse is 100/min, and respirations are 14/min. Several shallow ulcers are present in her mouth. Abdominal examination shows tenderness in the right lower quadrant without rebound. Rectal examination shows mucus. Rectosigmoidoscopy is unremarkable. An x-ray film of the abdomen shows gas in the small and large bowels. Laboratory studies show: Hb 10.2 g/dL, WBC 16,500/cmm, Platelet count 530,000/cmm, ESR 48/hr. Which of the following is the most likely diagnosis?

63) A 65-year-old man treated for heart failure with enalapril and digoxin presents to the emergency department (ED) with palpitations. His blood pressure is 160/100 mmHg, and heart rate is 110/min. His rhythm is irregular. His lungs are clear on auscultation. His abdomen is soft and non-distended. Mild epigastric tenderness is elicited on deep palpation. ECG shows atrial fibrillation without acute ischemic changes. Cardiac enzyme levels are normal. Treatment with warfarin and verapamil is initiated, and the patient is eventually discharged home. After two weeks, he returns to the ED to complain of profound anorexia. Which of the following is the most likely cause of his current complaint?

64) A 52-year-old Caucasian male comes to you for a routine health check-up. You decide to do age-appropriate screening in this patient and order a colonoscopy. The colonoscopy is normal, except for a 1.5cm polyp in the left descending colon. A colonoscopic polypectomy is done and the biopsy results are pending. The patient is anxious to know the expected biopsy results and the risk of cancer. Which of the following types of polyps is considered to be most premalignant?

65) A 50-year-old white male comes to the physician's office because of diarrhea, abdominal pain and weight loss. He has bulky, foul-smelling stools, abdominal distension and flatulence. He also has arthralgias and a chronic cough. His temperature is 37.8°C (100°F), blood pressure is 120/80 mm Hg, pulse is 80/min, and respirations are 18/min. Physical examination shows generalized lymphadenopathy, skin hyperpigmentation and a diastolic murmur in the aortic area. Small bowel biopsy shows villous atrophy with numerous PAS-positive materials in the lamina propria. Which of the following is the most likely diagnosis?

66) A 27-year-old male returning home after a three-month visit to Puerto Rico presents with diarrhea for the past 6 weeks. Other accompanying symptoms include cramps, gas, fatigue and progressive weight loss. Abdominal auscultation shows hyperactive bowel sounds, and borborygmi. The family history is unremarkable for intestinal disease. Laboratory studies show anemia with a hematocrit of 25% and MCV of 105fl; stool examination for ova and parasites is negative. Small intestinal mucosal biopsy shows blunting of villi with infiltration of chronic inflammatory cells, including lymphocytes, plasma cells, and eosinophils. Which of the following is the most likely diagnosis?

67) A 37-year-old male prisoner has been complaining of fever, chills and abdominal pain over the last week. He vomited once before reaching the emergency room. On physical examination, his blood pressure is 112/63 mmHg and his heart rate is 115/min. Breath sounds are diminished at the left lung base and there is marked left upper quadrant tenderness. Laboratory values are given below:WBC count 23,500/mm3, Neutrophils 65%, Bands 11%, Hemoglobin 12.5 mg/dL, Platelets 250,000/mm3, Total bilirubin 3.1 mg/dL, AST 46 units/L, AL T 70 units/L, Alkaline phosphatase 120 units/L. CT scan of the abdomen reveals a fluid collection within the spleen. Which of the following is the most likely diagnosis?

68) A 40-year-old female presents with a 12-month history of episodes of chest pain and dysphagia. The episodes last from a few seconds to a few minutes. She has not had weight loss, fevers or chills. Chest-x ray, ECG and barium swallow show no abnormalities. Manometric studies show simultaneous high amplitude contractions with normal relaxation of the lower esophageal sphincter. Which of the following is the most likely diagnosis?

69) A 29-year-old man presents to the ED complaining of RLQ pain for 24 hours. He states that the pain first began as a dull feeling around his umbilicus and slowly migrated to his right side. He has no appetite, is nauseated, and vomited twice. His BP is 130/75 mm Hg, HR is 95 beats per minute, temperature is 100.9°F, and his RR is 16 breaths per minute. His WBC is 14,000/μL. As you palpate the LLQ of the patient’s abdomen, he states that his RLQ is painful. What is the name of this sign?

70) A 55-year-old man with hypertension and end-stage renal disease requiring hemodialysis presents with 2 days of painless hematochezia. He reports similar episodes of bleeding in the past, which were attributed to angiodysplasia. He denies abdominal pain, nausea, vomiting, diarrhea, and fever. His vitals include HR of 90 beats per minute, BP of 145/95 mm Hg, RR of 18 breaths per minute, and temperature of 98°F. His abdomen is soft and nontender and his stool is grossly positive for blood. Which of the following statements are true regarding angiodysplasia?

71) A 70-year-old woman presents to the ED with dark stool for 3 weeks. She occasionally notes bright red blood mixed with the stool. Review of systems is positive for decreased appetite, constipation, and a 10-lb weight loss over 2 months. She denies abdominal pain, nausea, vomiting, and fever, but feels increased weakness and fatigue. She also describes a raspy cough with white sputum production over the previous 2 weeks. Examination reveals she is pale, with a supine BP of 115/60 mm Hg and HR of 90 beats per minute. Standing BP is 100/50 mm Hg, with a pulse of 105 beats per minute. Which of the following is the most likely diagnosis?

72) A 52-year-old man has episodes of severe chest pain associated with dysphagia. He has been seen twice in the emergency room, and both times the symptoms responded to sub-lingual nitroglycerin. He then had a full cardiac evaluation including electrocardiogram (ECG), cardiac biomarkers, and an exercise stress test, which were all normal. Which of the following is the most likely diagnosis?

73) A 16-year old girl has recently been referred to your family practice. She is a recent immigrant from Southeast Asia, and has been taking isoniazid (INH) and rifampin for uncomplicated tuberculosis. Routine blood tests are unremarkable, except for an elevated direct bilirubin. Other liver enzymes and function tests are completely normal. Which of the following is the most likely diagnosis?

74) A 78-year-old woman is brought to the ED by EMS complaining of vomiting and abdominal pain that began during the night. EMS reports that her BP is 90/50 mm Hg, HR is 110 beats per minute, temperature is 101.2°F, and RR is 18 breaths per minute. After giving her a 500 mL bolus of NS, her BP is 115/70 mm Hg. During the examination, you notice that her face and chest appear jaundiced. Her lungs are clear to auscultation and you do not appreciate a murmur on cardiac examination. She winces when you palpate her RUQ. An ultrasound reveals dilation of the common bile duct and stones in the gallbladder. What is the most likely diagnosis?

75) A 62-year-old man with a history of hypertension presents to the ED with severe constant mid-epigastric pain for the past hour. Over the last several months, he has had intermittent pain shortly after eating, but never this severe. He states he now has generalized abdominal pain that began suddenly about 15 minutes ago. He has no history of trauma, has never had surgery, and takes no medications. His vitals include HR of 115 beats per minute lying supine, increasing to 135 when sitting up, BP of 170/105 mm Hg supine, falling to 145/85 mm Hg when sitting up. He appears pale. His abdomen is rigid and diffusely tender with guarding and rebound. Bowel sounds are absent and stool hemoccult is positive. The white blood cell (WBC) count is 8500/μL, hemoglobin 8.5 mg/dL, hematocrit 27%, and platelets 255/μL. Which of the following is the most likely diagnosis?

76) The physician on call is called to the well-baby nursery because a full-term, African-American boy who is 49 hours old has not passed meconium. The pregnancy was uncomplicated. The neonate’s blood pressure is 70/50 mm Hg, heart rate is 140/min, and respiratory rate is 36/ min. The neonate is crying but is easily consolable. His abdomen is markedly distended. A barium enema is ordered, which shows dilated proximal bowel and a narrowed distal segment. Which of the following would provide a definitive diagnosis in this child?

77) A pregnant 16-year-old girl with no prior pre-natal care presents to the emergency department in labor. A male infant is delivered precipitously. Prenatal laboratory test results are unknown. There is no meconium. He has a birth weight of 3 kg (6 lb 10 oz). He is pink and is crying, heart rate is 130/min, and respiratory rate is 36/min, with good respiratory effort. The emergency medicine resident notices the infant has ascites and a membrane-covered anterior abdominal mass at the base of his umbilical cord. Which of the following is the most likely diagnosis?

78) A 50-year-old man is brought to the ED by ambulance with significant hematemesis. In the ambulance, paramedics placed two large-bore IVs and began infusing normal saline. In the ED, his HR is 127 beats per minute, BP is 79/45 mm Hg, temperature is 97.9°F, RR is 24 breaths per minute, and oxygen saturation is 96%. On physical examination, his abdomen is nontender, but you note spider angiomata, palmar erythema, and gynecomastia. Laboratory results reveal WBC 9000/μL, hematocrit 28%, platelets 40/μL, aspartate transaminase (AST) 675 U/L, alanine transaminase (ALT) 325 U/L, alkaline phosphatase 95 U/L, total bilirubin 14.4 mg/dL, conjugated bilirubin 12.9 mg/dL, sodium 135 mEq/L, potassium 3.5 mEq/L, chloride 110 mEq/L, bicarbonate 26 mEq/L, blood urea nitrogen (BUN) 20 mg/dL, creatinine 1.1 mg/dL, and glucose 150 mg/dL. Which of the following is the most likely diagnosis?

79) An 81-year-old diabetic woman with a history of atrial fibrillation is transferred to your emergency department (ED) from the local nursing home. The note from the facility states that the patient is complaining of abdominal pain, having already vomited once. Her vital signs in the ED are temperature 100.1°F, blood pressure (BP) 105/75 mm Hg, heart rate (HR) 95 beats per minute, and respiratory rate (RR) 18 breaths per minute. You examine the patient and focus on her abdomen. Considering that the patient has not stopped moaning in pain since arriving to the ED, you are surprised to find that her abdomen is soft on palpation. You decide to order an abdominal radiographic series. Which of the findings on plain abdominal film is strongly suggestive of mesenteric infarction?

80) A 71-year-old obese man is brought to the ED complaining of constant left mid quadrant (LMQ) abdominal pain with radiation into his back. His past medical history is significant for hypertension, peripheral vascular disease, peptic ulcer disease, kidney stones, and gallstones. He smokes a pack of cigarettes and consumes a pint of vodka daily. His BP is 145/80 mm Hg, HR is 90 beats per minute, temperature is 98.9°F, and RR is 16 breaths per minute. Abdominal examination is unremarkable. An ECG is read as sinus rhythm with an HR of 88 beats per minute. An abdominal radiograph reveals normal loops of bowel and curvilinear calcification of the aortic wall. Which of the following is the most likely diagnosis?

84) A 23-year-old woman presents to the ED with RLQ pain for the last 1 to 2 days. The pain is associated with nausea, vomiting, diarrhea, anorexia, and a fever of 100.9°F. She also reports dysuria. The patient returned 1 month ago from a trip to Mexico. She is sexually active with one partner but does not use contraception. She denies vaginal bleeding or discharge. Her last menstrual period was approximately 1 month ago. She has a history of pyelonephritis. Based on the principles of emergency medicine, what are the three priority considerations in the diagnosis of this patient?

85) A 28-year-old man presents with symptoms of frequent bowel movements, crampy abdominal pain, and the passage of mucus. There is no history of any bloody diarrhea, but recently, he developed joint discomfort in his hands, knees, and back. On examination he is thin, and his abdomen is soft with voluntary guarding in the left lower quadrant. His joints are not actively inflamed and there is an asymmetric distribution. Which of the following is the most likely diagnosis?

86) A 64-year-old white woman presents to her primary care physician complaining of difficulty and pain with swallowing, as well as occasional chest pain. She has a history of breast cancer treated with lumpectomy and radiation, hyper- tension, high cholesterol, and ovarian polyps. She indicates that her current problem started with liquids, but has progressed to solids, and that the food “just gets stuck in my throat.” The chest pain was once so bad that she took one of her husband’s nitroglycerin pills and the pain subsided, but it has since occurred many times. The physician orders an x-ray of the chest, but it is not diagnostic. Manometry is conducted, and it shows uncoordinated contractions. Which of the following is the most likely diagnosis?

87) A 22-year-old woman presents with chronic diarrhea. She has no abdominal discomfort, feels well, and reports no weight loss or systemic symptoms. Physical examination reveals a healthy young woman who is 5’7” tall and weighs 150 lb. The complete physical examination is normal. Which of the following is the most likely cause of a secretory diarrhea in this young woman?

88) A full-term 5-day-old African-American girl is taken to the pediatrician because her “eyes look yellow.” She is being exclusively formula- fed with an iron-rich formula. She has six wet diapers a day and stools twice a day. The pregnancy was uncomplicated and she was delivered by spontaneous vaginal delivery. Her Apgar scores were 9 and 10 at 1 and 5 minutes, respectively. Her temperature is 37°C (98.6°F), her head circumference is in the 50th percentile, and her weight is 3420 g (3 g below her birth weight). Her sclerae are icteric. There is no hepatomegaly or splenomegaly. Her total bilirubin is 9 mg/dL and her conjugated bilirubin is 0.2 mg/dL. Hemoglobin is 15 g/dL. Which of the following is the most likely diagnosis?

89) A 20-year-old man presents to the ED with fever and severe right lower quadrant (RLQ) pain for 1 day. Prior to this episode, he reports 2 months of crampy abdominal pain, generalized malaise, a 10-lb weight loss, and occasional bloody diarrhea. On examination, his HR is 115 beats per minute, BP is 125/70 mm Hg, RR is 18 breaths per minute, and temperature is 100.8°F. His only significant past medical history is recurrent perirectal abscesses. On physical examination, the patient appears uncomfortable and has a tender mass in the RLQ, without guarding or rebound. Rectal examination is positive for trace heme-positive stool. An abdominal computed tomographic (CT) scan reveals no periappendiceal fat stranding. There is inflammation of the distal ileum and several areas of the colon. There are no rectal inflammatory changes. Which of the following is the most likely diagnosis?

90) A 55-year-old white woman with a history of iron deficiency anemia has had intermittent trouble swallowing solids for the past few years. She denies alcohol or tobacco use. Her vital signs are stable. Her iron level is 40μg/dL and total iron binding capacity is 500 μg/dL. Other laboratory tests are within normal limits. Which of the following is the most likely diagnosis?

91) A 64-year-old woman develops sudden-onset abdominal discomfort after eating a large meal. The pain is constant, localizes to the epigastric area with radiation to her right scapula. She also has nausea and vomiting. It eventual subsides 1 hour later. An ultrasound of the abdomen reveals a dilated common bile duct secondary to stones. Which of the following statements regarding common bile duct stones is most likely true?

92) A 30-year-old man complains of chronic diarrhea for the past 6 months. There is no weight loss, fever, or abdominal pain. He takes no medications and feels fine. His physical examination is completely normal. Further history reveals that this man does not take laxatives; however, in an effort to stay slim he eats a lot of sugar-free gum and sugarless candy. Which of the following explanations is the most likely cause of his diarrhea?

93) A 16-year-old girl is referred to the office because of chronic diarrhea and weight loss. She is experiencing large-volume watery diarrhea that is painless. The symptoms persist even when she is fasting, and there is no relationship to foods or liquids. She is not on any medications, and there is no travel history or other constitutional symptoms. Her physical examination is normal. Which of the following is the most likely diagnosis?

94) A 52-year-old man has suffered with chronic diarrhea for several years, but has refused to see a doctor. He finally comes because he is having trouble driving at night, because of difficulty seeing. Physical examination reveals a slender, pale, unwell-looking man. He has a microcytic anemia, low calcium, and albumin levels. Which of the following is the most likely cause for his diarrhea?

95) The physician on call is paged to the well-baby nursery because a full-term, 3-hour-old boy has had green emesis twice, once after each of his feedings. He is being breast-fed. He was born by spontaneous vaginal delivery following a pregnancy complicated by polyhydramnios. His Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. His temperature is 37°C (98.6°F), blood pressure is 70/50 mm Hg, pulse is 150/min, and respiratory rate is 24/ min. His upper abdomen is distended, soft, and without palpable masses. Air is visualized in the duodenum and the stomach on x-ray. Which of the following is the most likely diagnosis?

99) A 50-year-old woman undergoes screening colonoscopy at her primary care physician’s recommendation. She has no family history of colorectal cancer. A single lesion is removed during the procedure and sent for pathologic examination. Which of the following findings carries the greatest risk of malignancy?

100) A 24-year-old woman presents to her primary care provider because of bloody diarrhea for several months and uveitis. Complete blood cell count shows mild anemia but a normal WBC count. The erythrocyte sedimentation rate and the C-reactive protein level are not elevated. Which of the following is the most likely diagnosis?

101) A 66-year-old woman presents to her physician because of recurrent painless bleeding on defecation over the past month. She has regular, soft bowel movements and no history of constipation or diarrhea. A recent diagnosis of aortic stenosis was an incidental finding on echocardiogram. She takes calcium and vitamin D supplements daily. Her last colonoscopy (at age 60) was normal. Heart rate is 82/min, blood pressure is 133/72 mm Hg, respiratory rate is 12/min, and temperature is 36.6°C (97.8°F). Physical examination reveals her conjunctivae are pink and mucosa is moist. She has no abdominal tenderness or palpable masses and no hemorrhoids or fissures. Stool is hemoccult positive. Colonoscopy shows a spider-like lesion in the ascending colon. Which of the following is the most likely diagnosis?

102) A 61-year-old woman is brought to the emergency department drowsy and disoriented, able only to follow simple commands. On examination her abdomen is distended and nontender, her skin has a yellow hue, and there are multiple spider nevi on her chest. In her purse, the physician finds prescriptions for peginterferon and ribavirin. When asked to raise her hands, the physician notices a coarse tremor. Laboratory tests show: Blood urea nitrogen: 17 mg/dL Creatinine kinase: 1.1 mg/dL Aspartate aminotransferase: 89 U/L Alanine aminotransferase: 93 U/L Total bilirubin: 3.1 mg/dL Ammonia: 124 μg/dL Which of the following is the most likely diagnosis?

104) A 51-year-old man describes 1 week of gradually worsening scrotal pain and dysuria. He is sexually active with his wife. His temperature is 100.1°F, HR 81 beats per minute, BP 140/75 mm Hg, and oxygen saturation is 99% on room air. On physical examination, his scrotal skin is warm and erythematous. A cremasteric reflex is present. The posterior left testicle is swollen and tender to touch. Color Doppler ultrasonography demonstrates increased testicular blood flow. Urinalysis is positive for leukocyte esterase. What is the most likely diagnosis?

105) A 40-year-old woman presents to the ED complaining of fever and 1 day of increasingly severe pain in her RUQ. She denies nausea or vomiting and has no history of fatty food intolerance. The patient returned from a trip to Mexico 6 months ago. About 2 weeks ago she experienced intermittent diarrhea with blood-streaked mucus. Her BP is 130/80 mm Hg, HR is 107 beats per minute, temperature is 102°F, and RR is 17 breaths per minute. Physical examination reveals decreased breath sounds over the right lung base. Abdominal examination shows tenderness to percussion over the RUQ and normal active bowel sounds. There is no Murphy sign. Her WBC is 20,500/μL. Chest radiograph reveals a small right-pleural effusion. Which of the following is the most likely diagnosis?

106) A 20-year-old man presents with several weeks of painful rectal bleeding. He denies fever, nausea, or vomiting. He is sexually active with women only and usually uses condoms. He denies any history of CD, UC, or malignancy. He states that the pain is most severe during and immediately after defecating. Bleeding is bright red and only enough to stain the toilet paper. Which of the following is the most common etiology of painful rectal bleeding?

107) A premature newborn is being treated in the neonatal intensive care unit. On the sixth day of life he is noted to be lethargic and in mild respiratory distress. His heart rate is 162/min, blood pressure is 55/38 mm Hg, and respiratory rate is 56/min. In addition to a distended abdomen, he has guaiac-positive stools. X-ray of the abdomen shows gas bubbles within the bowel wall. From what potentially life-threatening condition is this patient most likely suffering?

108) A 65-year-old man comes to the emergency department complaining of left lower abdominal pain that began the prior morning. He became concerned when he developed bloody diarrhea overnight. He has experienced similar pain, although to a lesser degree, over the past 2 months, especially after eating. The pain usually resolved within 1–2 hours, and he never had bloody diarrhea. His past medical history is significant for coronary artery disease and hypertension. He has smoked one pack of cigarettes per day for the past 30 years. On physical examination he is afebrile, heart rate is 90/min, and blood pressure is 135/85 mm Hg. He is visibly uncomfortable but in no apparent distress. His abdominal examination is significant for left lower quadrant tenderness but no guarding or rebound. Which of the following is the most likely diagnosis?

109) A 25-year-old previously healthy man experiences fatigue and malaise. One week ago he had a “viral” type illness consisting of a sore throat, fever, and myalgias. He now appears jaundiced, but the rest of the physical examination is normal. His investigations reveal a total bilirubin of 4 mg/dL (0.1–1.0 mg/dL) and a direct bilirubin of 0.3 mg/dL (0.0–0.3 mg/dL). Which of the following is the most likely diagnosis?

110) A 49-year-old man is brought to the ED by EMS stating that he vomited approximately three cups of blood over the last 2 hours. He also complains of epigastric pain. While examining the patient, he has another episode of hematemesis. You decide to place an NG tube. You insert the tube, confirm its placement, and attach it to suction. You retrieve 200 mL of coffee-ground blood. What is the most common etiology of an upper GI bleed?

111) A 63-year-old woman with cirrhosis caused by chronic hepatitis C is hospitalized because of confusion. She has guaiac-positive stools and a low-grade fever. She has received lorazepam for sleep disturbance. On physical examination, the patient is confused. She has no meningeal signs and no focal neurologic findings. There is hyperreflexia and a nonrhythmic flapping tremor of the wrists. Which of the following is the most likely explanation for this patient’s mental status change?

112) A 40-year-old white male complains of weakness, weight loss, and abdominal pain. On examination, the patient has diffuse hyperpigmentation and a palpable liver edge. Polyarthritis of the wrists and hips is also noted. Fasting blood sugar is 185 mg/dL. Which of the following is the most likely diagnosis?

113) A 55-year-old white woman has had recurrent episodes of alcoholinduced pancreatitis. Despite abstinence, the patient develops postprandial abdominal pain, bloating, weight loss despite good appetite, and bulky, foul-smelling stools. KUB shows pancreatic calcifications. In this patient, you should expect to find which of the following?

115) A 55-year-old male comes to you with complaint of fatigue for the past month. He also complains of occasional heartburn. His past medical history is significant for hepatomegaly, secondary to fatty liver. He has been drinking 3-4 shots of alcohol per day for the past 30 years. He denies smoking. His physical examination reveals pallor of skin and mucous membranes, and mild hepatomegaly. His laboratory report shows: Hb 8.5 g/dl, WBC 8,000/cmm, MCV 110 fl, Platelets 150,000/cmm, Blood glucose 118 mg/dl, BUN 16 mg/dl, Serum creatinine 1.0 mg/dl. What is the most likely cause of anemia in this patient?

116) A 62-year-old Caucasian man presents to your office with occasional ear pain and a lump in his neck. His past medical history is significant for hypertension treated with hydrochlorothiazide and diabetes mellitus treated with metformin. He smokes two packs of cigarettes per day and consumes alcohol occasionally. He is not sexually active. Physical examination reveals a hard, non-tender submandibular mass that is 3 cm in diameter. Chest examination is unremarkable. Abdomen is soft and non-tender. The liver span is 8 cm and the spleen is not palpable. His extremities have no cyanosis, clubbing, or edema. Complete blood count is within normal limits. Which of the following is the most likely cause of this patient's complaint?

117) A 67-year-old woman comes to her physician because she is feeling tired, all the time. She thinks that it is due to multiple surgeries she had over the past several years. She had two caesarian sections at the age of 22 and 26. She also had a thyroid surgery for Graves’s disease, 30 years ago. 12 years ago she was diagnosed with colon cancer and had undergone left hemicolectomy. She denies smoking or alcohol use. Her vitals are Temperature 36.7°C (98.2°F); BP 138/86 mm Hg; PR 77/min; RR 12/min. She looks markedly pale and has weakness in all four extremities. There is some sensory loss in lower limbs. The test for occult blood was negative. Labs came back as: Sodium 144 mEq/L, Potassium 4.2 mEq/L, Bicarbonate 24mEq/L, Blood urea nitrogen 18mg/dl, Creatinine 1.0 mg/dl, Glucose 82 mg/dl, WBC 8,600/cmm, Hemoglobin 7.9, Hematocrit 25%, Platelets 176,000/cmm. The physician decides to further investigate anemia and order RBC indices and peripheral blood smear. The results are: MCV 120 fl, MCH 36 pg, MCHC 28%, Reticulocyte count 04%. Peripheral smear showed anisocytosis, poikilocytosis, 4+ macrocytes, polychromatophilia and basophilic stippling. A whole new bunch of tests are ordered and the following report is seen on the computer. Vitamin B12 106 pg/ml (N=210-911 pg/ml), Serum Folate 16.4 ng/ml (N=2.8-17.8 ng/ml), Serum Bilirubin 1.8 mg/dl, Serum LDH 2500 U/L. Gastric analysis demonstrated an absence of hydrochloric acid. What is the most probable cause of her anemia?

118) A 34-year-old Caucasian man presents to your office with easy fatigability, difficulty concentrating, insomnia, and occasional muscle pain. He also complains of right hand clumsiness and some memory loss. He does not smoke and drinks one to two cans of beer on the weekends. Physical examination reveals extensor weakness of the right hand. Ankle reflexes are symmetric and there is no Babinski reflex. Laboratory studies show: Hemoglobin 8.5 g/dl, MCV 81 fl, AST 18 U/L, ALT 16 U/L, Bilirubin 0.8 mg/dl, Creatinine 2.1 mg/dl. Which of the following is most important in revealing the cause of this patient's condition?

119) A 26-year-old woman presents to your office complaining of fatigue. Her past medical history is insignificant. She was adopted in Greece and came to the United States when she was three years old. Her menstrual periods are regular and bleeding lasts three days. She does not use tobacco, alcohol, or illicit drugs. She takes no medication. Laboratory studies show: Complete blood count: Hemoglobin 10.1 g/L, MCHC 28%, MCV 70 fL, Platelets 200,000/mm3, Leukocyte count 7,500/mm3, Neutrophils 56%, Eosinophils 1%, Lymphocytes 33%, Monocytes 10%. Fecal occult blood test is negative. Iron therapy is initiated. When the patient returns four weeks later, her lab findings are essentially the same. This patient most likely suffers from:

120) An 8-month-old pale child is referred by a nurse practitioner due to "pale mucous membranes, irritability, and listlessness." The stool examination is negative for occult blood, ova and parasites. Laboratory studies reveal: Hemoglobin 6.0 g/L, MCHC 25%, MCH 16.5 pg, MCV 68 fl, Reticulocytes 0.6%, Platelets 230,000/mm3, Leukocyte count 5,500/mm3, Neutrophils 56%, Eosinophils 1%, Lymphocytes 33%, Monocytes 10%, Serum Iron 40 mg/dL, TIBC 460 mg/dL (normal 300-350 mg/dL), Percent saturation of transferrin 8.7%, Total serum bilirubin 0.9 mg/dL. The peripheral blood smear shows marked anisocytosis, microcytosis, hypochromia, and poikilocytosis. Which of the following is the most likely diagnosis?

121) A 54-year-old Caucasian man presents to his family physician's office complaining of several months of increased fatigability. He eats meat occasionally and drinks two to three cans of beer on weekends. Physical examination reveals pale conjunctivae and hyperdynamic carotid pulses. His blood hemoglobin level is 7.7 mg/dl, WBC count is 4,500/mm3, and platelet count is 170,000/mm3 Folic acid therapy is initiated. Four weeks later the patient's hemoglobin level is 9.1 mg/dl, but he complains of new tingling in his toes. Which of the following is a likely cause of this patient's current symptoms?

122) A 46-year-old bank executive is referred to the clinic by her dentist. For the past 6 weeks, she has had swollen, bleeding gums. She appears pale and feels weak. She smokes half a pack of cigarettes daily and drinks alcohol socially. Her family history is not significant. Her vital signs are stable. She is afebrile. WBC 44,100 mm3, Hemoglobin 9.0 g/dL, Hematocrit 27%, Platelets 16,000/mm3. Leukocyte distribution: Blast forms 79%, Promonocytes 12%, Monocytes 8%, Lymphocytes 1%. Cytochemical analysis:Sudan black: slightly positive, Alpha-naphthyl esterase: positive, PAS reaction: negative. Which of the following is the most likely diagnosis?

123) A 65-year-old woman is being evaluated for "generalized depression." She has felt weak and fatigued ever since her husband died 4 months ago. She does not have any suicidal thoughts, but is losing interest in her daily activities. She quit smoking 24 years ago, and drinks 1-2 beers weekly. Physical examination reveals pallor and cervical lymphadenopathy. Blood work reveals: Hemoglobin 12.0 g/L, MCV 85 fl, Platelets 224,000/mm3, Leukocyte count 54,500/mm3, Neutrophils 16%, Lymphocytes 75%, Monocytes 9%. Some variants of lymphocytes and smudge cells are present. Which of the following is the most likely diagnosis?

124) A 54-year-old male is brought to the emergency department because of severe abdominal pain and diarrhea for the past 24 hours. He is confused and crying out in pain. His temperature is 38.6°C (101.6°F), blood pressure is 82/58 mm Hg, pulse is 118/min, and respirations are 24/min. Physical examination reveals extensive abdominal distention. There is fresh blood in his stools. Intravenous administration of normal saline is started after drawing blood for the necessary laboratory tests. The results of these tests are: Sodium 136 mEq/L, Potassium 3.6 mEq/L, Bicarbonate 18 mEq/L, Blood urea nitrogen 32 mg/dL, Creatinine 1.3 mg/dL, Glucose 86 mg/dL, WBC 35,000/mm3, Hemoglobin 13.0 g/dL, Hematocrit 36%, Platelets 460,000/mm3. Leukocyte distribution:Promyelocyte 2%, Myelocytes 7%, Metamyelocytes 18%, Bands 32%, Segmented neutrophils 24%, Lymphocytes 15%. The patient's temperature continues to remain elevated during the night of admission. A broad-spectrum antibiotic is added to the IV infusion. Repeat CBC on the following morning shows a WBC count of 118,000/mm3 with essentially the same differential distribution of leukocytes. His leukocyte alkaline phosphatase score is elevated. What is the most probable diagnosis of this patient?

125) A 25-year-old African American man presents to your office complaining of nocturia over the past several months. He reports having to wake to urinate 2 to 3 times per night despite restricting his fluid intake. He denies any back pain, fever, dysuria, or urinary urgency. His past medical history is significant for recurrent otitis media in childhood and hepatitis A infection two years ago. He is sexually active with one partner and does not use condoms. His brother died of a "blood disease" at age 10. The man's hematocrit is 49%. Urinalysis reveals no proteinuria or sediment abnormalities. His nocturia is most likely related to:

126) A 25-year-old African American male comes to the office with sudden-onset back pain, dark urine and an one day history of fatigue. Two days ago, he was started on trimethoprim-sulfamethoxazole for his sinusitis. Otherwise, his past medical history is unremarkable. Physical examination reveals significant pallor. His laboratory report shows: Hb 7.5 g/dl, Total bilirubin 3.5 mg/dl, Direct bilirubin 0.8 mg/dl, Haptoglobin decreased, LDH increased. The peripheral smear shows bite cells. His G6PD level is normal. Which of the following is the most likely cause of his hemolysis?

127) A 75-year-old Caucasian male comes to the office for his routine medical check-up. He complains of fatigue for the past month. His previous medical history is significant for calcified aortic valves and hypertension. His vital signs are stable; except for a blood pressure of 150/90 mm Hg. Physical examination reveals pallor and a 4+ ejection systolic murmur in the aortic area. Lab reports show: Hb 9 g/dl, MCV 75 fl, Reticulocyte count increased, Serum LDH increased, Haptoglobin decreased, Peripheral smear fragmented RBC. Which of the following is the most likely cause of this patient's anemia?

128) A 68-year-old unconscious man is brought to the emergency department by a hospice nurse. He had seizures 2 hours ago, after which he lost consciousness. The hospice staff responded by securing his airway and giving him 2L of oxygen. He is in hospice for terminal care for stage IV esophageal carcinoma. He also had a part of his finger removed 1.5 years ago due to a skin cancer. His pulse oximetry reading is 91%. His temperature is 37.9°C (100.2°F), respirations are 23/min, pulse is 96/min, and blood pressure is 140/85 mmHg. He does not respond to painful stimuli. Rectal examination reveals a hard, irregular surface of an enlarged prostate. His recent prostate specific antigen level is 40. MRI shows an intracranial lesion with bleeding inside, and these findings are consistent with metastasis. What is the most likely diagnosis?

129) A 44-year-old woman comes to the office with complaints of weight loss and blood in her stools for the last year. Her mother is on chemotherapy for colon carcinoma. Her maternal uncle also had colon cancer, as did her first cousin who died of colon cancer at the age of 46. She is very worried that she might have the same cancer. Based on her history, she falls within the criteria for Lynch syndrome (also known as HNPCC/ Hereditary Nonpolyposis Colorectal Cancer). Apart from the complete work-up for colon cancer, this patient should be evaluated for which of the following condition?

130) A 72-year-old Hispanic man comes to the clinic with complaints of mild headache and lethargy for the past several days. He complains of cough for the past 12 years but, has been bothering him more lately. The cough is mucoid in nature. He has noticed blood in it once in a while. He has been smoking 1 pack/day for 29 years. His Temperature 37C (98.6F); BP 120/84 mmHg; PR 78/min; RR 24/min. On examination of the lungs, adventitious sounds are heard in all the lobes and scant basilar crackles. Laboratory studies show: WBC 7,600/mm3, Hemoglobin 13.6, Hematocrit 40%, Platelets 214,000/mm3, Sodium 131 mEq/L, Potassium 3.6 mEq/L, Bicarbonate 18 mEq/L, Blood urea nitrogen 16 mg/dL, Creatinine 0.6 mg/dL, Glucose 95 mg/dL, Serum osmolality 260 mOsm/kg (275-295 mosm/kg H2O), Urine osmolality 310 mOsm/kg (38-1400 mosm/kg H2O). A chest x-ray shows a 2-centimeter left upper lobe nodule and mediastinal adenopathy your diagnosis is?

131) A 63-year-old Caucasian man reports occasional palpitations when exercising. He denies chest pain. Past medical history includes coronary artery disease status post coronary artery stenting, mitral valve replacement with mechanical valve, and diabetes mellitus. He consumes a well-balanced diet and takes one multivitamin tablet daily. His medications include warfarin, simvastatin, metoprolol, lisinopril, and metformin. Physical examination reveals conjunctival pallor and heart sounds consistent with the presence of a mechanical mitral valve. His hematocrit is 30%. The peripheral blood smear shows occasional schistocytes and his serum LDH level is elevated. His stool is negative for occult blood. Which of the following is the most likely cause of this patient's anemia?

132) An 80-year-old female is brought to your office, by her son, because of severe fatigue. She lives alone and is suffering from severe degenerative joint disease, which puts her in a house arrest-type state. Her son usually helps with getting grocery. Her only other medical problem is hypertension. She takes hydrochlorothiazide and acetaminophen. Her vitals are stable. On examination, she has pallor, and evidence of severe degenerative joint disease. Which of the following is the most likely cause of pallor in this patient?

133) A 56-year-old white male comes to the office for a health maintenance visit. He feels healthy, and is "enjoying life as much as possible in a stressed environment." He smokes 2-3 packs of cigarettes daily and drinks socially. His temperature is 37°C (98.6°F), blood pressure is 160/94 mm Hg, pulse is 78/min, and respirations are 14/min. Physical examination reveals plethora of the face and moderate splenomegaly. Blood tests show the following: WBC 15,600/mm3, Hemoglobin 17 gm/dl, Hematocrit 52%, Platelets 550,000mm3, RBC count 7.5 million, Sodium 141 mEq/L, Potassium 3.6 mEq/L, Bicarbonate 22 mEq/L, Blood urea nitrogen 16 mg/dl, Creatinine 0.6 mg/dl, Glucose 95 mg/dl. The erythrocyte indices are all within normal range. What is the most probable diagnosis?

134) A 49-year-old woman comes to the office and complains of a "strange, itchy rash" on her left areola which has been present for the last month. She tried applying various lotions and creams, but the lesion did not resolve. She denies having other skin conditions, except for a poison ivy rash 2 months ago. She does not take any medications and feels "goofy" when she takes penicillin. Physical examination reveals an eczemoid lesion on the left nipple. No abnormality is visible on the mammogram. Biopsy demonstrates large cells surrounded by halo-like areas which invade the epidermis. What is the most likely diagnosis?

135) A 41-year-old fire-fighter comes to your office and requests for prostate cancer screening. He is concerned because his elder brother was recently diagnosed with prostate cancer, and he read in the paper that "cancers run in families." He requests to be screened urgently, as he "cannot even think of life with such a deadly disease." He has no medical complaints. He has been your patient for the past 6 years, and has no other medical history. He is on a very balanced diet, and adds that he eats a lot of garlic "so that cholesterol remains in check." He takes a low-dose aspirin daily. He does not smoke, and is only a social drinker. He admits using marijuana "once in a while” What is the best next step to address this patient's concerns?

136) A 27-year-old male presents with dyspnea and fatigue. He has no family history of asthma, heart disease or any blood disorder. His vital signs are stable, and he is afebrile. The only significant findings on examination are pallor and splenomegaly. Lab studies show: Hematocrit 20%, WBC count 4,000/micro-L, Platelet count 85,000/miro-L, Bilirubin 7 mg/dl, Direct bilirubin 1.2 mg/dl, Serum LDH 500 U/L (normal value is 80-280 U/L), Serum haptoglobin 20mg/dl (normal value is 30-220 mg/dl). Peripheral blood smear shows microcytic hypochromic cells. Serum ferritin is low while total iron binding capacity (TIBC) is elevated. Reticulocyte count is 5 %. Urine dipstick testing is positive for hematuria and microscopy of urine shows 1 RBC/HPF. Repeated G6PD assays are normal. Coomb's and micro-Coomb's tests are negative. Bone marrow examination shows hypocellular marrow. Based on these findings, what is the most likely diagnosis?

137) A 44-year-old man who comes to the office because he has had several episodes of hemoptysis for the past two months. He admits to smoking 2-3 packs of cigarettes daily for the last 24 years. Physical examination and chest x-ray are very suggestive of a lung malignancy. Chest CT and bronchoscopy with biopsy are done, and the patient goes on vacation in Aruba. The patient returns to the office after one week, and you are now holding the biopsy result in your hands. It reads, "The tumor has spread to the hilar and mediastinal lymph nodes with bony extension." Which of the following is the most appropriate opening statement?

138) A 25-year-old male presents to his physician with dyspnea and fatigue for the last few weeks. He is a non-smoker. He denies any family history of asthma or blood disorders. He does not take any medications. Examination shows pallor, scleral icterus and splenomegaly. Lab tests show the following: Hematocrit 20%, WBC count 10,000/micro-L, Platelet count 180,000/miro-L, Total Bilirubin 7 mg/dl, Direct bilirubin 1 A mg/dl, BUN 10 mg/dl, Serum creatinine 0.7 mg/dl, Serum LDH 400 U/L (normal value is 80-280 U/L), Serum haptoglobin 160mg/dl (normal value is 30-220 mg/dl ), Reticulocyte count 8 %. Peripheral blood smear shows spherocytes with central pallor. Osmotic fragility and direct Coombs' tests are positive Based on these findings, what is the most likely diagnosis?

139) A 10-year-old white boy is brought to the office by his foster parents for the evaluation of severe pain in his left knee for the last few days. His left knee has been hurting so bad that he is now unable to play with his peers. The pain is continuous and non-radiating. His knee appears swollen, but he denies any history of trauma. His family history is unknown. His vital signs are stable. Physical examination reveals a pale young boy. The left knee is tender, erythematous and swollen. Blood tests reveal: WBC 12,600/mm3, Hemoglobin 9.3 g/dl, Hematocrit 29%, Platelets 201,000/mm3, ESR 40. X-ray of the knee reveals that the lower end of the femur has a central lytic lesion, onion skinning and a moth-eaten appearance with some extension into the soft tissue. What is the most likely diagnosis?

140) A 56-year-old woman is complaining of cough for the past 4 months. The cough was dry initially, but only yesterday she was scared-to-death to see phlegm with blood. She is not feeling well and thinks that she has lost "a lot of weight" recently, despite no apparent change in her diet. She swears that she has never smoked a cigarette in her life. There is no history of night sweats nor contact with any person with similar complaints. She is a housewife who rarely drinks, and can't think of using recreational drugs. She is completely faithful to her husband. Her husband is also a "religious non-smoker". Her vitals are stable and lung examination reveals no significant findings. Her chest x-ray shows 1.5cm lesion in the right peripheral lung field and no evidence of any hilar or mediastinal lymph node enlargement. What is the most probable diagnosis?

141) A 74-year-old immigrant from Colombia comes to the office and complains of having "all sorts of problems of old age." He has pain all over his body. He often has headaches and feels dizzy. He has visual problems, and finds it difficult to walk. For the last several weeks, he has been feeling weak and numb in his feet. He lives with his son, and is not happy with the way his son treats him; however, he denies receiving any form of physical abuse. His past medical history is unremarkable. His mother had "some blood disease." His vital signs are stable. Physical examination reveals multiple bruises on his body, and sensory deficits in his feet. Other significant findings include lymphadenopathy and hepatosplenomegaly. Ophthalmoscopy shows dilated, segmented, and tortuous retinal veins. Laboratory studies show: WBC 10,200 /mm3, Hemoglobin 9.6 g/dl, Hematocrit 29%, Platelets 94,000 /mm3, Sodium 141 mEq/L, Potassium 3.6 mEq/L, Blood urea nitrogen 18 mg/dl, Creatinine 0.8 mg/dl, Glucose 115 mg/dl. Serum protein electrophoresis reveals an lgM spike. Which of the following is the most likely diagnosis in this patient?

142) A 25-year-old white female presents to the clinic with persisting pain in her wrists and ankles for the last 3 months. The pain is 3/10 in intensity, and partially relieved by ibuprofen. She also has a rash on her face. She denies smoking, and drinks alcohol occasionally. Her temperature is 37.3°C (99.2°F), blood pressure is 120/80 mm Hg, pulse is 79/min, and respirations are 18/min. Physical examination reveals swollen joints of the hands and ankle, as well as erythema over the bridge of the nose and the upper cheeks. There is no muscle weakness. Labs show: Hemoglobin 11.0 g/dL, Hematocrit 33%, Platelets 240,000/mm3, WBC 13,600/mm3. Leukocyte distribution:Segmented neutrophils 76%, Lymphocytes 20%, Bands 2%, Monocytes 2%. RF, ANA, and antibodies to double stranded-DNA are positive in high titers. What is the most likely diagnosis?

143) A 23-year-old man presents to the emergency room complaining of severe abdominal pain. He has also suffered from nausea and vomiting for several hours. His past medical history is insignificant, but his brother has had similar problems. He denies risky sexual behavior and intravenous drug use. On exam, his temperature is 38.8°C (101.8°F), heart rate is 102/min, and respirations are 14/min. There is tenderness in the right upper quadrant exacerbated by deep inspiration. The liver span is 7 cm. His spleen is palpated 2 cm below the left costal margin. There are no peritoneal signs. Which of the following is the most likely diagnosis?

144) A 60-year-old Vietnam war veteran comes for his annual examination. He does not have any complaints, other than getting tired very quickly. Physical examination reveals pallor and an enlarged spleen. CBC reveals: WBC 14,000/cmm, Hemoglobin 9.9 g/dL, Hematocrit 30%, Platelets 100,000/cmm. The lymphocytes have fine, irregular cytoplasmic projections. Cytochemical testing reveals a strong acid phosphatase reaction, which is not inhibited by tartaric acid. What is the most probable diagnosis?

145) A 47-year-old woman comes to the office and complains of burning abdominal pain which has been present for the past 3 months, is grade 6/10 in severity, continuous, and relieved by taking antacids. She also complains of some constipation. Her father has a history of "ulcers in his belly." She works as a floor secretary in a surgical ward, and is not happy with her new boss. She denies any weight loss or decreased appetite. Her temperature is 37.1°C (98.8°F), blood pressure is 130/85 mm Hg, heart rate is 78/min, and respirations are 14/min. She is awake, alert, and oriented. The abdominal examination reveals normoactive bowel sounds and tenderness in the epigastric region, but no palpable mass. Her stools are occult blood positive. ECG reveals increased PR and shortened QT intervals. The laboratory results reveal the following: Sodium 137 mEq/dL, Potassium 4.2 mEq/dL, Chloride 101 mEq/dL, Bicarbonate 27 mEq/dL, Calcium 12.0 mg/dl, Phosphorus 2.2 mg/dl, BUN 37 mg/dl, Creatinine 1.8 mg/dl. Which of the following is the most likely diagnosis?

146) A 21-year-old Caucasian man bumped into a table in his living room two days ago and now presents to the emergency department with a swollen and tender right thigh. Pulsation is decreased over the right popliteal artery. His uncle suffered from a "blood clotting disease". This patient's history is most likely to reveal which of the following episodes in his past?

147) A 7-year-old Caucasian boy is brought to your office for a routine check-up. He underwent splenectomy one year ago for persistent anemia and jaundice. He has received pneumococcal vaccination and takes penicillin prophylaxis. His uncle underwent splenectomy for "some blood disorder" in his childhood. His blood hemoglobin level is 11.5 mg/dL and MCV is 90 fl. Blood smear demonstrates occasional red blood cells with single, round, blue inclusions on Wright stain. The latter finding is most likely related to?

148) A 25-year-old white female presents with a 5-day history of sore throat, extreme fatigue, and headaches. She has just returned from a spring break in Jamaica where she had "the time of her life." She smokes 2-3 cigarettes daily and occasionally drinks alcohol. Her vital signs are stable. She is afebrile. Physical examination reveals posterior cervical lymphadenopathy, mild splenomegaly, and exudative pharyngitis. Palatal petechiae are present. CBC shows: WBC 16,000/cmm with 55% lymphocytes, Hemoglobin 13 .5gm/dl, Hematocrit 4 1%, Platelets 216,000/cmm. Many variant forms of lymphocytes are seen, including cells with convoluted nuclei and highly vacuolated cytoplasm. Rapid streptococcal throat test, urinalysis, and heterophilic antibody test are all negative. What is the most likely diagnosis?

149) A 2-year-old boy is brought by his mother to the emergency department because of a high-grade fever which "does not go away" with acetaminophen. For the last four days, the child has been very irritable and is crying a lot. He is also pulling his ear and not eating well. He has been generally well, other than the occasional sore throat this season. His temperature is 38.8°C (102.2°F), blood pressure is 90/60 mm Hg, pulse is 119/min, and respirations are 24/min. He appears well nourished, but is irritable. Physical examination reveals enlarged cervical lymph nodes and splenomegaly. The tympanic membranes are inflamed. CBC shows: WBC 81,100 /mm3, Hemoglobin 8.0 g/dL, Hematocrit 25%, Platelets 16,000 /mm3, Blast forms 80%, Prolymphocytes 10%, Lymphocytes 10%. The blast cells have condensed nuclear chromatin, small nucleoli and scant agranular cytoplasm. Subsequent histochemical staining reveals strongly positive periodic acid Schiff (PAS) reaction. No Auer rods were seen. Which of the following is the most likely diagnosis?

150) A 34-year-old woman comes to the office for her annual examination. She has been your patient for the last 4 years. She eats a lot of meat, but does not like fruits and vegetables. Her menstrual period began at age 12. She has two children, who are ages 13 and 11. She is in a monogamous relationship with her husband, and uses oral contraceptive pills. She smokes 1/2 pack of cigarettes daily, and drinks alcohol socially. Her mother had breast disease and had an operation, but died 1 month after the surgery due to a heart attack. She has read in "US Health News" that breast cancer is the leading culprit for cancer death among non-smoking women. She now asks you, "What is the most important risk factor for breast cancer?" What is the correct response to this patient's question?

151) A 54-year-old male had undergone an emergency colonic resection following an extensive ischemic colitis. The surgery was uneventful. The patient has been on peperacillin and tazobactam (Zosyn) for the past five days. He was NPO (nothing by mouth) for the past five days. He has a significant alcoholic history. On postoperative day six, he developed bleeding from the venipuncture site. His temperature is 36.7° C (98° F), blood pressure is 120/76 mmHg, pulse is 80/min, and respirations are 16/min. Lab results are: Hb 11.5g/dL, MCV 88 fl, Platelet count 160,000/cmm, Leukocyte count 7,500/cmm, Segmented neutrophils 68%, Bands 1%, Eosinophils 1%, Lymphocytes 24%, Monocytes 6%, Prothrombin time 20 sec (INR=1.9), Partial thromboplastin time 45 sec. His family history is insignificant. Which of the following is the most likely cause of his condition?

152) A 16-year-old boy is brought to the office by his basketball coach because, "he is unable to work out with other boys." For the past several weeks, the boy has been complaining of left knee pain which is dull and worsens with running, especially on the court. In addition, he thinks he has lost some weight. He does not smoke or drink alcohol. He is sexually active with many partners, and does not use condoms. His vital signs are stable. On examination, his left knee is swollen and tender. X-ray reveals a sclerotic lesion in the distal femur with periosteum lifted and a "sun burst appearance”. What is the most likely diagnosis?

153) A 54-year-old female with megaloblastic anemia and ataxia is given radiolabeled cobalamin by mouth followed by an intramuscular injection of unlabeled cobalamin. The urine radioactivity level measured afterwards is determined to be normal. Which of the following is the most likely cause of this patient's symptoms?

154) An 18-year-old boy comes to clinic to discuss an embarrassing problem. For the last 6 weeks he has noticed a painless mass in his right testis. This is not bothering him at all, but it is becoming larger. He is afraid that his girlfriend may notice it and find out about his other partners. He has multiple partners, and does not use condoms. He has no fever and no other medical complaints. His cousin has SLE but otherwise family history is unremarkable. On ultrasound you suspect testicular cancer and order a few tests. Results are as follows: Alpha-fetoprotein (AFP) Increased, Beta subunit of the human chorionic gonadotropin (hCG) Normal, Placental Alkaline phosphate (PLAP) Normal, Carcinoembryonic antigen (CEA) Slightly Increased, Lactate Dehydrogenase (LDH) Increased. What could be the most likely diagnosis?

155) Elizabeth, a 13-year-old girl, comes with complaints of new onset seizures. She has morning headaches that go away after vomiting. She also has history of colonic polyps, for which she is undergoing work-up. Her family history is significant for her mother having problems with polyps. (She underwent proctocolectomy.) Initial non-contrast T1-weighted MRI shows a large, heterogeneous, hypointense mass in the white matter of the right temporal lobe and extending into the parietal and occipital lobes. The lower signal area within the mass suggests tissue necrosis. What is the most likely diagnosis in this patient?

156) A 72-year-old Caucasian man presents to your office complaining of severe fatigue. He says that five months ago he was able to climb four flights of stairs without shortness of breath, but now he has to rest after two. His appetite has decreased, but he denies any abdominal discomfort or black stool. Physical examination reveals firm, enlarged cervical and supraclavicular lymph nodes. A soft I/VI grade systolic murmur is heard along the left sternal border. Abdomen is soft and non-tender. His liver span is 10 cm and the spleen is palpated 4 cm below the left costal margin. His blood hemoglobin level is 7.5 mg/dl. Which of the following is the most likely cause of this patient's anemia?

157) A 54-year-old male comes to the physician's office because of chronic cough and recent bloody sputum. He used to smoke 2 packs of cigarettes daily for 22 years, but he quit last month. His other symptoms are weight loss, anorexia, constipation, increased thirst, and easy fatigability. He thinks that he is depressed because his wife died 4 months ago and "life never felt the same after that." On examination, he is a slim man who appears pale. His vital signs are stable, although he appears a little irritable and short of breath. Laboratory and radiologic studies reveal: Sodium 144 mEq/dL, Potassium 4.3 mEq/dL, Chloride 98 mEq/dL, Bicarbonate 21 mEq/dL, Calcium 11.5 mg/dl, BUN 28 mg/dl, Creatinine 0.8 mg/dl. Chest x-ray hilar mass in the left lung. Biopsy of the mass would most likely reveal?

158) A 24-year-old man from Long Island, New York, presents with fever, drenching sweats, and malaise for the past week. For the last few days, he has noted jaundice and dark-colored urine. He recalls being bitten by a tick two weeks ago. His surgical history includes splenectomy after a car accident 10 years ago. He does not use tobacco, alcohol, or illicit drugs. His temperature is 39.5°C (103°F), pulse is 106/min, and blood pressure is 110/70 mm Hg. Systemic examination is unremarkable, except for jaundice. Based on these findings, what is the most likely diagnosis?

159) A 55-year-old pig farmer is brought to the emergency department (ED) after having a seizure two hours ago. During his transit to the ED, he has another seizure. On arrival, he is unconscious, pulseless, and not breathing. Resuscitation is successful and the patient is stabilized; however, he does not do well over the next several days and is eventually declared dead. His wife says that he had been healthy most of his life, except for the past few weeks, when he was complaining of headaches. Autopsy shows multiple fluid-filled cysts in the brain parenchyma. Which of the following is the most likely diagnosis of this patient?

160) A 34-year-old recently migrated African American male presents with severe headache and high-grade fever with chills for the last two days. He also complains of severe malaise, myalgia and vomiting. He adds that the present episode started with feeling of intense cold and chills with shivering followed by high-grade fever. He had two similar episodes in the past, when he was in Africa. His vitals are: T° 38.9°C (102°F), RR 20/min, PR 110/min and BP100/60 mm Hg. He has pallor with mild splenomegaly but rest of his physical examination is normal. What is the most likely diagnosis in this patient?

161) A 22-year-old man comes to the urgent care clinic with a one-week history of fever, sore throat, and malaise. He has tried several over-the-counter products with partial relief. His temperature is 38.8°C (102°F), pulse is 110/min, respirations are 18/min, and blood pressure is 130/70 mm Hg. Oropharyngeal examination reveals palatal petechiae with streaky hemorrhages and blotchy, red macules. The tonsils are enlarged and covered with whitish exudate. Mild jaundice is present. Enlarged lymph nodes are palpable posterior to the sternocleidomastoid muscle bilaterally. Axillary lymphadenopathy is also present. Abdominal examination reveals normal bowel sounds and mild hepatosplenomegaly. His complete blood count is shown below: Hemoglobin 14.0 g/L, MCV 88 f l, Platelets 140,000/mm3, Leukocyte count 14,500/mm3, Neutrophils 33%, Lymphocytes 66%, Eosinophils 1%. Which of the following is commonly associated with this patient's condition?

162) A 36-year-old man from Ohio presents with fever, malaise, fatigue, and skin lesions on his right forearm. His fever is low-grade, without any rigors or chills. His temperature is 38.4°C (101°F), pulse is 87/min, and blood pressure is 124/74mm Hg. Examination shows 1-2cm warty, heaped-up skin lesions with a violaceous hue and sharply demarcated border. Some of these lesions are crusted. Wet preparation of purulent material from skin lesions shows yeast Based on these findings, what is the most likely diagnosis?

163) A 34-year-old male comes to the physician's office due to a severely pruritic lesions on his hands. He denies any trauma but recalls using his hands to change the sand of his children's sandbox when they went to Miami Beach three days ago. He later developed pruritic, erythematous papules over his arm. These papules progressed to serpiginous, reddish brown, elevated lesions, which are evident bilaterally on the upper extremities on exam. What is the most likely diagnosis?

164) A 64-year-old male recovering from an upper respiratory infection develops malaise and productive cough. Two days later he presents to the emergency department with confusion and severe dyspnea. He reports coughing up copious amounts of yellowish sputum streaked with blood today. On physical examination, his temperature is 40°C (104°F), blood pressure is 150/90 mm Hg, pulse is 110/min, and respirations are 24/min. Chest x-ray reveals infiltrates in the lung midfields bilaterally as well as multiple thinwalled cavities. What is the most likely cause of this patient's condition?

165) A 35-year-old man presents to the office with a two-week history of low-grade fever and progressive weakness. He has "a heart murmur detected a long time ago." He denies illicit drug use. Physical examination reveals splinter hemorrhages, small petechiae on the palatal mucosa, and an audible murmur. His ESR is 60/min. Urinalysis reveals microscopic hematuria and 1 +proteinuria. Which of the following valvular dysfunctions is most likely to be detected?

166) A 22-year-old female presents with a two-day history of inability to close her right eye, a low-grade fever, and a rash on her trunk. There is no burning or itching associated with the rash. She denies headache, confusion, neck stiffness, numbness, and tingling. She went on a camping trip in Vermont four weeks ago but cannot recall any exposure to ticks. She was treated for chlamydia! Urethritis infection in the past. She has been using over-the-counter acetaminophen for fever; she noticed the rash after beginning the acetaminophen. Physical examination reveals several erythematous lesions around her waistline. Neurological examination shows right-sided facial nerve palsy. Based on these findings, what is the most likely diagnosis?

167) A 22-year-old male student presents with an acute onset of fever, double vision, and painful swelling around his eyes. He also has significant muscle pain in his neck and jaw muscles. A week earlier, he experienced a period of abdominal pain, nausea, vomiting, and diarrhea, all of which resolved spontaneously. He has a history of intravenous drug abuse but has recently completed of a drug rehabilitation program. He is febrile. Physical examination shows "splinter" hemorrhages, periorbital edema, and chemosis. Chest is clear to auscultation. Cardiac exam reveals no murmur. Abdomen is soft and nontender with no organomegaly. His complete blood count is shown below: Hemoglobin 13.0 g/L, MCV 85 fl, Platelets 228,000/mm3, Leukocyte count 10,500/mm3, Neutrophils 56%, Eosinophils 21%, Lymphocytes 23%. Based on these findings, what is the most likely diagnosis?

168) A 19-year-old woman comes to the physician because of fever, joint pain, and rash. The rash started on her face and is spreading down her body. She has pain in her fingers, wrists, and knees. She denies any neck stiffness, nausea, or vomiting. She has been sexually active with multiple partners. Her vaccination status is unknown. Her pulse is 86/min, blood pressure is 125/75 mm Hg, and temperature is 37.7°C (99.8°F). Physical examination reveals a maculopapular rash on her face and chest. Posterior auricular, cervical, and suboccipital lymphadenopathy is present. She has mild conjunctivitis. Oropharynx is clear. Chest is clearto auscultation. What is the most likely diagnosis?

169) An elderly bedridden patient in the hospital develops cough, fever, and shortness of breath. On examination, the JVP is 4 cm, heart sounds are normal, and there are crackles on inspiration in the right lower lobe. A CXR reveals a new right lower lobe infiltrate and his WBC is 15,000/mL. He was admitted to the hospital 7 days ago for the treatment of congestive heart failure. Which of the following is the most likely diagnosis?

170) A 35-year-old male complains of inability to close his right eye. Examination shows facial nerve weakness of the upper and lower halves of the face. There are no other cranial nerve abnormalities, and the rest of the neurological examination is normal. Examination of the heart, chest, abdomen, and skin show no additional abnormalities. There is no lymphadenopathy. About one month ago the patient was seen by a dermatologist for a bull’s-eye skin rash. The patient lives in upstate New York and returned from a camping trip a few weeks before noting the rash. Which of the following is the most likely diagnosis?

171) An 18-year-old woman presents with headache, anorexia, chilly sensations, and discomfort on both sides of her jaw. She has also noticed discomfort in both lower abdominal quadrants. Physical examination reveals bilateral enlarged parotid glands that are doughy, elastic, and slightly tender; with a reddened orifice of Stensen’s duct. Her abdomen is soft with bilateral lower quadrant abdominal tenderness; a temperature of 38.5°C; and a pulse rate of 92/min. Laboratory data show hemoglobin 13 g/dL; hematocrit 40%; white blood cells (WBC) 9000/mL, with 35% segmented neutrophils, 7% monocytes, and 58% lymphocytes. Which of the following is the most likely cause for her abdominal pain and tenderness?

172) A 20-year-old woman presents with headache, fever, and neck stiffness. On examination, her blood pressure is 100/70 mm Hg, pulse 100/min, temperature 38.6°C, and the neck is stiff and painful to flex and extend. The ears, throat, and sinuses are normal, there are no focal neurologic signs, and the remaining examination is normal. There are no reported similar cases in the community. Which of the following is the most likely source of her infection?

173) A 32-year-old woman acutely develops high fever, hypotension, and rash. This is followed by vomiting, diarrhea, confusion, and abdominal pain. In the hospital, evidence of multiorgan failure develops. Desquamation of the skin occurs 1 week after the acute illness. On further history, the illness started 3 days after the onset of menstruation. Which of the following is the most likely diagnosis?

175) A 22-year-old man is an avid spelunker (cave explorer) and has recently been exploring several caves. A routine CXR taken for a new job reveals hilar adenopathy and two patches of pneumonitis. His physical examination is completely normal. Careful questioning reveals he has just gotten over a cold with mild fever, cough, and malaise. Which of the following is the most likely diagnosis?

176) A 53-year-old man with alcoholic cirrhosis presents with increasing jaundice and abdominal discomfort. He reports no fevers or chills. On examination, his blood pressure is 100/60 mm Hg, pulse 100/min, temperature 38.1°C. He has a distended abdomen, peripheral edema, and shifting dullness. The abdomen is tender and bowel sounds are present. A diagnostic paracentesis is performed; the total cell count is 940/mL with polymorphonuclear neutrophils (PMNs) equal to 550/mL, Gram stain is negative, and cultures are pending. Which of the following is the most likely diagnosis?

177) A 20-year-old woman presents with headache, anorexia, chilly sensations, pain, and drawing sensations in both sides of her jaw. She has also noticed discomfort in both lower abdominal quadrants. Physical examination reveals bilateral enlarged parotid glands that are doughy, elastic, and slightly tender; with a reddened orifice of Stensen’s duct. Her abdomen is soft with bilateral lower quadrant abdominal tenderness, a temperature of 38.5°C, and a pulse rate of 92/min. Laboratory data show hemoglobin 13 g/dL; hematocrit 40%; WBC 9000/mL, with 35% segmented neutrophils, 7% monocytes, and 58% lymphocytes. Which of the following is the most likely diagnosis?

178) An 18-year-old woman visits her physician because of 3 weeks of malaise, 2 weeks of fever, and a sore throat. Physical examination shows pharyngeal infection with enlarged tonsils and a patchy, white exudate; enlarged, palpable anterior and posterior cervical, axillary, and inguinal lymph nodes; tenderness in the right upper quadrant; and minimal splenomegaly. Laboratory data show hemoglobin 14 g/dL; hematocrit 42%; platelets 380,000/mL; WBC 8500/mL, with 35% segmented neutrophils, 1% eosinophils, and 64% lymphocytes, of which 36% were atypical. Which of the following is the most likely diagnosis?

179) A 43-year-old man developed a cough shortly after returning from a 1-month hiking trip in California. While there, he was hiking in the central California valleys. During his trip, he had developed a flu-like‖ illness consisting of fever, cough, and muscle pains, which resolved spontaneously. A CXR shows a thin-walled cavity in the right upper lobe, and the sputum reveals fungal elements. Which of the following is the most likely causative organism?

180) A 34-year-old man presents with diarrhea 3 weeks after returning from a trip to rural South America. Over the past few days, he has gradually developed lower abdominal pain and diarrhea. Now the symptoms are much worse with eight stools a day consisting mostly of mucus and blood. He is afebrile, the abdomen is tender in left lower quadrant, and the remaining examination is normal. His stool is mostly comprised of blood and mucus, and stools tests show trophozoites of Entamoeba hitolytica. Which of the following is the most likely site of extra intestinal involvement?

181) A 40-year-old man develops erythema nodosum, conjunctivitis, and a pleural effusion. Over several weeks, pulmonary lesions lead to cavitation and a large, thin-walled cavity. He was traveling in Arizona before becoming ill. Sputum samples reveal mature spherules. Which of the following is the most likely diagnosis?

183) A 7-year-old child, unvaccinated because of his parents’ religious beliefs, develops malaise, cough, coryza, and conjunctivitis with a high fever. Examination of his mouth reveals blue white spots on a red base beside his second molars. The next day he develops an erythematous, nonpruritic, maculopapular rash at his hairline and behind his ears, which spreads over his body. Which of the following is the most likely diagnosis?

184) A 51-year-old man is admitted to the hospital because of renal failure. His past medical history is significant for recurrent episodes of bilateral flank pain over the past several years as well as nocturia 2 to 3 times per night for the past 10 years. He has no weight loss. On physical examination, his blood pressure is 160/100 mm Hg. His mucous membranes are pale. There is a palpable mass located at the right flank. Which of the following is the most likely diagnosis?

185) A 30-year-old African American man comes to the physician because of a two-week history of fatigue and ankle edema. He is HIV-positive. He takes no medications. He does not use tobacco, alcohol, or drugs. His temperature is 36.7°C (98°F), blood pressure is 140/86 mm Hg and respirations are 16/min. Physical examination shows mild ankle edema. Laboratory studies show: Hb 12.5 g/dl, WBC 6,000/cmm, Platelets 140,000/cmm, Serum Na 135 mEq/L, Serum K 5.0 mEq/L, BUN 28 mg/dl, Serum creatinine 2.4 mg/dl. Urinalysis revealed 2+ proteinuria but otherwise shows no abnormalities. CD4 count taken three weeks ago was 550. Which of the following is the most probable form of kidney disease in this patient?

186) A 43-year-old man complains of occasional red urine. He denies fever, edema, flank pain or weight loss. Specifically, he says that each urine stream starts out transparent, but turns red by the end of the stream. At times he has noticed small clots in his urine. Physical examination is within normal limits. What is the most likely cause of his complaints?

187) A 74-year-old man comes to the physician because of a one-year history of increased urinary frequency and urgency. He feels that his bladder is "not emptying properly", and has a constant sensation of incomplete voiding. His only other medical problem is hypertension, for which he takes hydrochlorothiazide. He never had any surgeries. Urine culture shows no abnormality. Which of the following is true regarding this patient's disorder?

188) A 26-year-old man comes to the emergency department because of a sudden onset of severe, colicky, leftsided flank pain that radiates to the scrotum. He also has nausea, vomiting and dark-colored urine. He has never had these symptoms before. Examination shows no abnormalities. Non-contrast helical CT shows a 5 mm radiopaque stone in the left upper ureter. His laboratory studies are as follows: Serum calcium 9.8 mg/dl, Serum creatinine 0.9 mg/dl, BUN 15 mg/dl. Urinalysis shows hematuria but no casts. Which of the following is the most likely cause of this patient's symptoms?

189) A 36-year-old man comes to the physician because of fatigue and generalized edema. He was recently diagnosed with Hodgkin's lymphoma. Laboratory studies show: Serum sodium 145 mEq/L, Serum potassium 3.8 mEq/L, Serum albumin 2.0 g/dl, Serum globulin 7.0 g/dl, Total serum bilirubin 0.9 mg/dl, Serum creatinine 1.2 mg/dl. Urinalysis shows proteinuria 4+. Which of the following glomerulopathies is more likely to be present in this patient?

190) A 30-year-old woman comes to the physician because of a 2-day history of periorbital edema and abdominal distention. She has no other complaints. Her temperature is 37.1°C (98.9°F), blood pressure is 125/75 mm Hg, pulse is 80/min, and respirations are 14/min. Examination shows ascites. Urinalysis shows proteinuria; 24-hour urinary protein excretion is 4 g/day, total serum protein is 5 g/dl and serum albumin is 2.5g/dl. A diagnosis of nephrotic syndrome is made. Renal biopsy is performed. She is started on diuretics and her salt and protein intake is restricted. Her edema begins to improve. However, the patient suddenly develops severe abdominal pain, fever, and gross hematuria. Which of the following is the most likely diagnosis that will be revealed by renal biopsy?

191) A 30-year-old African American man comes to the physician because of a 2-day history of periorbital edema and abdominal distention. His temperature is 37.1°C (98.7°F), blood pressure is 125/75mm Hg, pulse is 80/min, and respirations are 14/min. His height is 170cm (5'7") and weight is 104kg (2301bs). He has been in a drug rehabilitation program for the past 2-months, for a long history of IV drug abuse. Examination shows significant ascites. Urinalysis shows proteinuria; 24-hr urinary protein excretion is 4g/day. Which of the following is the most likely diagnosis?

192) A 50-year-old man comes to the physician for a routine check-up. He has no present complaints. He has diabetes mellitus, type 2, stable angina, and gout. He takes glyburide and atenolol. He smokes two packs a day and, occasionally, consumes alcohol. His father had an early myocardial infarction; his brother has diabetes mellitus. His blood pressure is 140/90 mm Hg and heart rate is 65/min. Physical examination shows no abnormalities. There is concern about end organ damage in this patient due to diabetes mellitus. Which of the following is the earliest renal abnormality that could be seen in this patient?

193) A 70-year-old man presents to the emergency department with a 12-hour history of inability to void. He also complains of nocturia and problems with initiating micturition for the past few weeks. He denies fever, weakness, numbness, dysuria or hematuria. He does not use tobacco, alcohol, or drugs. Neurological examination shows no abnormalities, except absent Achilles tendon reflexes bilaterally. Straight catheterization of the bladder produces 600 ml of urine. Further evaluation will most likely show which of the following?

194) A 36-year-old man comes to the emergency department because of excruciating flank pain. The pain radiates to the groin. His temperature is 36.9°C (98.5°F), blood pressure is 115/75 mm Hg, pulse is 85/min, and respirations are 14/min. Urinalysis shows six RBCs/HPF. Laboratory studies show BUN of 12mg/dl and serum creatinine of 0.9mg/dl. X-ray film of the abdomen shows nephrocalcinosis and IVP shows multiple contrast filled cysts. Ultrasonogram of the kidneys is unremarkable. Which of the following is the most likely diagnosis?

195) A 22-year-old man comes to the physician because of a 2-day history of dark urine. He has had an upper respiratory tract infection for 3 days. His temperature is 37.1° C (98.9°F), blood pressure is 145/90mm Hg, pulse is 80/min, and respirations are 14/min. Examination shows no abnormalities. Laboratory studies show: Urinalysis: Glucose Negative, Protein 1+, Ketones Negative, Leukocyte esterase Negative, Nitrites Negative, WBC 3-6/hpf, RBC 30-50/hpf, Casts RBC. Serum chemistry: Serum Na 138 mEq/L, Serum K 4.5 mEq/L, Bicarbonate 22 mEq/L, BUN 30 mg/dL, Serum creatinine 1.8 mg/dL. Serum complement level is within normal limits. Which of the following is the most likely diagnosis?

196) A 27-year-old man comes to the physician because of red urine. He has had no pain or burning on urination. He has infiltrative pulmonary tuberculosis (diagnosed recently). He takes isoniazid, rifampin, and pyrazinamide. He smokes two packs a day and consumes alcohol occasionally. Vital signs are stable Physical examination shows no abnormalities. Which of the following is the most likely diagnosis?

197) An 18-year-old girl comes to the emergency department with a rash and arthralgias. She is sexually active and has had the same sexual partner for the past 4-months. Recent medical history is significant for an episode of dysuria and increased urinary frequency, both of which started 5-days ago. Her primary care physician prescribed TMP+SMX (Bactrim) for this. She developed her present symptoms 3-days after starting the medication. Her aunt has Lupus. Her temperature is 38.5°C (101.3°F), pulse is 86/min, and respirations are 16/min. Physical examination shows a disseminated maculopapular rash; there is no costovertebral tenderness or flank pain; serum creatinine is 2 mg/dL. Urinalysis shows 2-5 RBC/hpf, numerous white blood cell casts made mostly of eosinophils, and mild proteinuria. Which of the following is the most likely diagnosis?

198) A 26-year-old woman presents with a one-week history of dysuria and increased urinary frequency. She admits to having multiple sexual partners in the past. Her temperature is 37.1°C (98.9°F), blood pressure is 110/70 mm Hg, pulse is 68/min, and respirations are 15/min. Examination shows suprapubic tenderness. Mucopurulent discharge is observed at the urethral os. Urinalysis shows: Blood Negative, Glucose Negative, Ketones Negative, Leukocyte esterase Positive, Nitrites Negative, WBC 40-50/hpf, RBC 1-2/hpf, Bacteria None. Urine culture after 24hours < 100colonies/ml. Which of the following is the most likely diagnosis?

199) A 60-year-old man comes to the physician's office because of fatigue and hematuria. His past medical history is significant for fatty liver, gout, and anemia. He has smoked two packs of cigarettes daily for 40 years. He is a heavy alcohol drinker. His last visit to his physician was 1 month agoforthe 'flu'. His temperature is 37.1°C (98.9°F), blood pressure is 145/90mm Hg, pulse is 78/min, and respirations are 14/min. Examination shows no abnormalities. Dipstick testing is positive for hematuria. Laboratory studies show: Urinalysis: Glucose Negative, Ketones Negative, Leukocyte esterase Negative, Nitrites Negative, WBC 1-2/hpf, RBC 1-2/hpf, Casts Epithelial cell. Serum chemistry: Serum Na 140 mEq/L, Serum K 5.0 mEq/L, Bicarbonate 20 mEq/L, BUN 36 mg/dL, Serum creatinine 34 mg/dL. Which of the following is the most likely diagnosis?

200) A 50-year-old man comes to the physician because of a skin rash, joint pains, malaise and fatigue. He has a history of intravenous drug abuse. His temperature is 37.1°C (98.9°F), blood pressure is 140/90 mm Hg, pulse is 80/min, and respirations are 14/min. Examination shows palpable purpura and hepatosplenomegaly. Urinalysis shows hematuria, red blood cell casts and proteinuria. The results of the laboratory studies are as follows: BUN 30 mg/dl, Creatinine 2.0 mg/dl, Serum complement Low, Anti-HCV Positive. Which of the following is the most likely diagnosis?

201) A 27-year-old man comes to the physician because of a 2-day history of periorbital swelling. He was treated with oral dicloxacillin for a skin infection 3-weeks ago. His urine has turned darker. His temperature is 37.4°C (99.4°F), blood pressure is 150/90 mm Hg, pulse is 80/min, and respirations are 15/min. Examination shows periorbital swelling. Urinalysis shows 8 RBCs/HPF with RBC casts and a mild proteinuria. Laboratory studies show low serum C3 levels; BUN is 40 mg/dl and serum creatinine is 2 mg/dl. Which of the following is the most likely diagnosis?

202) A 27-year-old man comes into the emergency department because of a 2-week history of hemoptysis, breathing difficulty, ankle edema, and dark urine. His past medical history is insignificant. He is not taking any medication. He does not use tobacco, alcohol, or drugs. Laboratory studies show: Hb 10.5 g/dl, Serum Na 135 mEq/L, Serum K 4.8 mEq/L, BUN 36 mg/dl, Serum creatinine 2.8 mg/dl. Urinalysis shows numerous dysmorphic red blood cells/HPF, moderate proteinuria, and red cell casts. Chest x-ray reveals bilateral alveolar infiltrates. Diagnosis of which of the following pulmonary-renal syndromes require emergency plasmapheresis?

203) A 64-year-old man is scheduled for hemodialysis due to end stage renal disease. He has a several year history of hypertension, diabetes, coronary artery disease, hypercholesterolemia, peripheral vascular disease, gout, and diverticulosis. Six months ago, he was admitted for urosepsis. Recently, his haemoglobin has ranged between 8.5 to 9.5 g/dl. He has already been on iron therapy, and now you are considering erythropoietin injections twice weekly. Which of the following is most likely to be seen following erythropoietin therapy?

204) A 70-year-old man is brought to the hospital by his son because of worsening fatigue. His son states that his father does not like seeing doctors and has not seen a physician in the past 20 years. He has no medical problems. Physical examination of the prostate shows no abnormalities. Laboratory studies show: Hb 10.5 g/dl, WBC 7,400/cmm, Platelets 160,000/cmm, Serum Na 135 mEq/L, Serum K 5.0 mEq/L, BUN 50 mg/dl, Serum creatinine 3.0 mg/dl. Ultrasonogram of the abdomen shows bilateral small kidneys and no evidence of hydronephrosis. Kidney biopsy shows intimal thickening and luminal narrowing of renal arterioles with evidence of sclerosis. Which of the following is the most likely cause of this patient's findings?

205) A 35-year-old woman who recently emigrated from Russia comes to the physician because of hematuria. She has a history of frequent headaches. Extensive evaluation did not reveal the cause of her headaches. They occur almost every day, and she tried various analgesics to relieve them. Her family history is significant for hypertension and diabetes mellitus. She does not use tobacco, alcohol, or drugs. Her blood pressure is 120/70 mm Hg and heart rate is 80/min. Physical examination shows no abnormalities. Urinalysis shows numerous unchanged red blood cells/hpf. Which of the following is the most likely cause of this patient's condition?

206) A 55-year-old woman comes to the physician for an annual physical examination. She has no new complaints, except fatigue. She has an 8-year history of chronic low back pain; severe degenerative joint disease has been documented on MRI. She had an anterior wall myocardial infarction four years ago. Her current medications include naproxen, acetaminophen, oxycodone, aspirin, atenolol, and simvastatin. Her blood pressure is 130/80 mm Hg and pulse is 72/min. Laboratory studies show: Hb 10 g/dl, WBC 6,000/cmm, Blood sugar 82 mg/dl, BUN 36 mg/dl, Serum creatinine 2.0 mg/dl. Urinalysis : Protein 2+, Glucose Absent, RBC AbsentWBC 10-15/HPF, Nitrite Negative, Esterase Negative, Sediment WBC casts. Serum protein electrophoresis is negative for monoclonal gammopathy. Two years ago, her BUN level was 22 mg/dl, and creatinine level was 1.6 mg/dl. Which of the following is the most likely pathology involved in this patient's renal failure?

207) A 50-year-old man comes to the physician for a routine follow-up visit. He has hypertension, diabetes mellitus, secondary hyperparathyroidism, and end-stage renal disease. He has been on hemodialysis for the past three years. He was admitted three months ago for line sepsis, which was treated with antibiotics. He had a right below-the-knee amputation two years ago following a non-healing foot ulcer. Physical examination shows a right carotid bruit. If this patient dies within the next five years, what would be the most likely cause of his death?

208) A 15-year-old boy comes to the physician because of hematuria and lower abdominal pain. This is his third episode of hematuria in the past 2 years. He has a family history of renal disease. His temperature is 37.1°C (98.9°F), blood pressure is 140/90 mm Hg, pulse is 80/min, and respirations are 14/min. Examination shows mild sensorineural deafness bilaterally. Urinalysis shows hematuria and proteinuria. Laboratory studies show BUN of 50 mg/dl and serum creatinine of 3.1 mg/dL; serum complement levels are normal. Renal biopsy shows foam cells, and immunofluorescence shows no immunoglobulins or complement. Electron microscopy shows alternating areas of thinned and thickened capillary loops with splitting of GBM. Which of the following is the most likely diagnosis?

209) A 17-year-old African American man comes to the physician after an episode of gross hematuria that resolved spontaneously. He has no other complaints. His past medical history is insignificant. He takes no medications. He smokes occasionally. He does not use drugs or alcohol. His temperature is 36.7°C (98°F), blood pressure is 120/70 mm Hg, pulse is 70/min, and respirations are 14/min. Physical examination shows no abnormalities. Urinalysis shows many unchanged red blood cells/HPF, but is otherwise normal. Laboratory studies show a creatinine level of 0.9 mg/dl. Which of the following is the most likely diagnosis?

210) A 30-year-old woman comes to the physician due to several weeks history of generalized edema, fatigue, and decreased appetite. She has no other medical problems. She takes no medications. She does not use tobacco, alcohol, or drugs. Her temperature is 36.7°C (98°F), blood pressure is 110/70 mm Hg, pulse is 80/min, and respirations are 18/min. Physical examination shows generalized edema. Laboratory studies show a low serum albumin level. HBsAg is positive, and liver function tests are abnormal. Urinalysis shows +4 proteinuria and microhematuria. Which of the following is the most likely diagnosis?

212) A 64-year-old man presents with weight gain, shortness of breath, easy bruising, and leg swelling. On examination, his blood pressure is 140/80 mm Hg, pulse 100/min, JVP 4 cm, heart sounds normal, and lungs are clear. There is a 3+ pedal and some periorbital edema. Investigations include a normal chest x-ray (CXR), electrocardiogram (ECG) with low voltages, anemia, high urea and creatinine, and 4 g/day of protein in the urine. A renal biopsy, which shows nodular deposits that have an apple-green birefringence under polarized light when stained with Congo red. Which of the following is the most likely diagnosis?

213) A 25-year-old man is referred to you because of hematuria. He noticed brief reddening of the urine with a recent respiratory infection. The gross hematuria resolved, but his physician found microscopic hematuria on two subsequent first-voided morning urine specimens. The patient is otherwise healthy; he does not smoke. His blood pressure is 114/72 mm Hg and the physical examination is normal. The urinalysis shows 2+ protein and 10 to 15 RBC/hpf, with some dysmorphic erythrocytes. No WBC or casts are seen. What is the most likely cause of his hematuria?

214) A 17-year-old man is brought to the emergency room with confusion and incoordination. He is uncooperative and refuses to provide further history. Physical examination reveals an RR of 30; the vital signs are otherwise normal as is the general physical examination. Laboratory values are as follows: Na: 135 mEq/L, K: 2.7 mEq/L, HCO3: 15 mEq/L, Cl: 110 mEq/L. Arterial blood gases: PO2 92, PCO2 30, pH 7.28 Urine: pH 7.5, glucose—negative, Ca: 9.7 mg/dL, PO4: 4.0 mg/dL. Which of the following is the most likely cause of the acid base disorder?

215) A 28-year-old woman presents with a recent episode of coughing up some blood, frequent nosebleeds, and now decreased urine output. A nasal mucosa ulcer was seen on inspection. Her urinalysis is positive for protein and red cells consistent with a GN. The CXR shows two cavitary lesions and her serology is positive for antineutrophil cytoplasmic antibodies (ANCA). Which of the following is the most likely diagnosis?

216) A 74-year-old woman develops acute sepsis from pneumonia and is admitted to the intensive care unit because of hypotension. She is started on antibiotics, and her blood pressure is supported with intravenous normal saline. Despite this she remains oliguric and develops ARF. Her urinalysis has heme-granular casts and the urine sodium is 56 mEq/L. Which of the following is the most likely cause of her ARF?

217) A 76-year-old man presents to the emergency room. He had influenza and now presents with diffuse muscle pain and weakness. His past medical history is remarkable for osteoarthritis for which he takes ibuprofen, and hypercholesterolemia for which he takes lovastatin. Physical examination reveals blood pressure of 130/90 mm Hg with no orthostatic change. The only other finding is diffuse muscle tenderness. Laboratory data include: BUN: 30 mg/dL, Creatinine: 6 mg/dL, K: 6.0 mEq/L, Uric acid: 18 mg/dL Ca: 6.5 mg/dL, PO4: 7.5 mg/dL, UA: large blood, 2+ protein. Microscopic study shows muddy brown casts and 0 to 2 rbc/hpf (red blood cells/high power field).Which of the following is the most likely diagnosis?

218) A 73-year-old man undergoes abdominal aortic aneurysm repair. The patient develops hypotension to 80/50 mm Hg for approximately 20 minutes during the procedure according to the anesthesia record. He received 4 units of packed red blood cells. Postoperatively, his blood pressure is 110/70 mm Hg, heart rate is 110, surgical wound is clean, and a Foley catheter is in place. Over the next 2 days his urine output slowly decreases. His creatinine on post-op day 3 is 3.5 mg/dL (baseline 1.2). His sodium is 140 mEq/L, K 4.6 mEq/L, and BUN 50 mg/dL. Hemoglobin and hematocrit are stable. Urinalysis shows occasional granular casts but otherwise is normal. Urine sodium is 50 mEq/L, urine osmolality is 290 mosmol/L, and urine creatinine is 35 mg/dL. The FENa (fractional excretion of sodium) based on these data is 3.5. What is the most likely cause of this patient’s acute renal failure?

219) A 73-year-old woman with arthritis presents with confusion. Neurologic examination is nonfocal, and CT of the head is normal. Laboratory data include: Na: 140 mEq/L, K: 3.0 mEq/L, Cl: 107 mEq/L, HCO3: 12 mEq/L. Arterial blood gases: PO2 62, PCO2 24, pH 7.40. What is the acid-base disturbance?

220) A 63-year-old man alcoholic with a 50-pack-year history of smoking presents to the emergency room with fatigue and confusion. Physical examination reveals a blood pressure of 110/70 mm Hg with no orthostatic change. Heart, lung, and abdominal examinations are normal and there is no pedal edema. Laboratory data are as follows: Na: 110 mEq/L, K: 3.7 mEq/L, Cl: 82 mEq/L, HCO3: 20 mEq/L, Glucose : 100 mg/dL, BUN : 5 mg/dL, Creatinine: 0.7 mg/dL Urinalysis: normal Specific gravity: 1.016. Which of the following is the most likely diagnosis?

221) A 65-year-old white female comes to the ER because of persistent vomiting and epigastric pain. She has been suffering from left knee osteoarthritis for the past 6 years, and has been taking ibuprofen for the past year. She also has a history of chronic obstructive pulmonary disease but is well controlled on her current medications. She quit smoking a few years ago. Her laboratory results are given below: ABG: pH 7.55, PCO2 46 mm Hg. Chemistry panel: Serum sodium 132 mEq/L, Serum potassium 3.0 mEq/L, Chloride 88 mEq/L, Bicarbonate 38 mEq/L, Serum creatinine 0.8 mg/dl. Which of the following would describe her primary acid-base status?

222) A 36-year-old male is brought to the emergency department due to confusion, nausea and decreased arousal. He is unable to answer questions and no other history is available. His temperature is 36.7ׄ°C (98.2°F), respirations are 22/min and pulse is 86/min. His ABG and serum electrolyte levels are shown below: pH 7.21, PaO2 96 mmHg, PaCO2 28 mmHg, Serum sodium 140 mEq/L, Serum potassium 3.6 mEq/L, Chloride 90 mEq/L, Bicarbonate 12 mEq/L, Blood urea nitrogen (BUN) 30 mg/dl, Serum creatinine 1.2 mg/dl. What is the most likely primary acid-base disorder in this patient?

223) A 56-year-old male comes to the emergency room because of a 2-day history of fever, chills, shortness of breath and productive cough. He also threw up once in the emergency room. He has been smoking for several years and occasionally drinks alcohol. On admission, his BP was 90/60, but with one liter of normal saline it improved to 120/80 mm Hg. His temperature is 38.8°C (102°F). His arterial blood gas (ABG) analysis is as follows: Blood pH 7.53, PaO2 70 mmHg, PaCO2 30 mmHg, HCO3- 22 mEq/L. Which of the following best describes his primary acid-base status?

224) A 67-year-old male is brought to the ER because of increasing abdominal pain and nausea for the past few hours. He has multiple medical problems including type-2 diabetes, hypertension, hyperlipidemia, coronary artery disease, cerebrovascular accident, peripheral vascular disease, ischemic cardiomyopathy and atrial fibrillation. He has not been on anticoagulation because of recurrent bleeding peptic ulcer disease. He has had a cholecystectomy. He takes multiple medications at prescribed doses and lives at home with his family. He quit smoking 10 years ago and does not use alcohol or drugs. His temperature is 37.8°C (100.0°F), blood pressure is 150/90 mm Hg, pulse is 110/min and respirations are 22/min. Physical examination shows an elderly male in acute distress. Lungs have few crackles at the bases. Heart rate is irregular. Bowel sounds are decreased and diffuse tenderness is present. There is no peripheral edema. Initial laboratory studies show the following: Serum sodium 140 mEq/L, Chloride 103 mEq/L, Bicarbonate 14 mEq/L, Blood urea nitrogen (BUN) 20 mg/dl, Serum creatinine 0.8 mg/dl, Blood glucose 198 mg/dl, Amylase 255 U/L. Which of the following is the most likely diagnosis in this patient?

225) A 56-year-old male with a history of type-2 diabetes presents for a routine office visit. His blood work from two months ago showed hyperkalemia, and at that time his physician discontinued lisinopril. His repeat blood work done today is shown below: Chemistry panel: Serum sodium 136 mEq/L, Serum potassium 5.6 mEq/L, Chloride 110 mEq/L,Bicarbonate 18 mEq/L, Blood urea nitrogen (BUN) 26 mg/dl, Serum creatinine 1.9 mg/dl. He currently takes glipizide, furosemide, nifedipine and aspirin. His blood pressure is 150/90 mmHg. Examination is unremarkable. Which of the following is the most likely cause of his low bicarbonate and elevated potassium?

226) A 33-year-old woman is brought to the emergency room because of altered mental status. En route to the ER, she suffers a generalized tonic clonic seizure, and once at the hospital she is confused and no further history can be obtained. You know only that she has a history of schizophrenia. On physical examination, her temperature is 36.7°C (98°F), blood pressure is 130/76 mm Hg, pulse is 80/min, and respirations are 14/min. Examination shows normal pupils. Her chest is clear to auscultation and her heart sounds are normal. Her abdomen is soft and nontender. Extremities have no edema. Laboratory studies show: Serum sodium 118 mEq/L, Serum creatinine 0.8 mg/dL, Serum calcium 8.4 mg/dL, Serum glucose 98 mg/dL, Urine osmolality 100 mosm/kg, Urine specific gravity 1.002. Which of the following is the most likely cause of her symptoms?

227) A 56-year-old male comes to the emergency room because of increasing shortness of breath for the last 3 days. He had a cold recently, and since then his symptoms have been worse. He has a mild productive cough but denies fever or chills. He has a several year history of smoking and has been diagnosed with emphysema. He also has a history of diabetes, hypertension, hyperlipidemia, and hypothyroidism. He takes glipizide, metformin, lisinopril, furosemide, aspirin, atorvastatin and levothyroxine. Physical examination shows trace bilateral lower extremity edema and a diffuse decrease in breath sounds along with wheezing. Heart sounds are distant. His arterial blood gas shows the following: Blood pH 7.23, PaO2 88mm Hg, PaCO2 40 mm Hg, HCO3- 16mEq/L. Which of the following best describes the acid-base status of this patient?

228) A 45-year-old male is brought to the emergency department in a stuporous state. He appears agitated and disoriented. His temperature is 37.2°C (99°F), respirations are 22/min, pulse is 90/min and blood pressure is 110/70 mm of Hg. His lab findings are as follows: Blood pH 7.21, PaO2 100 mmHg, PaCO2 30 mmHg, HCO3- 13 mEq/L, Serum osmolarity 350 mOsm/L, Blood glucose 90 mg/dl, Na+ 141 mEq/L, K+ 4.6 mEq/L, Cl- 100 mEq/L, BUN 28mg/dl, Creatinine 2.5 mg/dl. His urine shows the presence of rectangular, envelope-shaped crystals. His creatinine three months ago was 1.2 mg/dl. What is the most likely cause of this lab abnormality in this patient?

229) A 21-year-old female comes to the office for the evaluation of fatigue and weakness. She first noticed these symptoms nine months ago. She says, "I can't exercise a lot anymore because I get fatigued very easily, but after resting for a while, I feel better, and my fatigue disappears." She then describes a recent episode of weakness while swimming in a pool, where she experienced double vision (especially when she did not look straight ahead), difficulty raising her eyelids, and swallowing problems. What is the most likely diagnosis?

230) A 27-year-old woman presents to the ER with severe vomiting and abdominal pain that started several hours ago. She describes her emesis as "yellowish." She has a history of alcohol and cocaine use. Her temperature is 36.7°C (98°F), pulse is 98/min, respirations are 16/min, and blood pressure is 140/86 mmHg. Physical examination reveals dryness of the oral mucosa. Her abdomen is soft, non-distended, and without hepatosplenomegaly. Mild epigastric tenderness is present on deep palpation. Bowel sounds are increased. No rebound or rigidity is noted. She is treated with intravenous normal saline and metoclopramide. Several hours later she complains of neck pain and her neck muscles are noted to be stiff and tender. Which of the following best explains this patient's current complaints?

231) A 55-year-old Caucasian male comes to the office because of numerous falls for the past few weeks. Yesterday, he felt so dizzy that he fell on the ground and hurt his knees. He has also noticed dry mouth, dry skin, and erectile dysfunction over this period. His past medical history is significant for the recent onset of resting tremors. He was diagnosed with diabetes six months ago, which is controlled with diet. His blood pressure is 120/80 mmHg supine, and 90/60 mmHg standing. Physical examination reveals rigidity and bradykinesia. What is the most likely diagnosis of this patient?

232) A 65-year-old, obese, white female comes to the office for the evaluation of her progressively worsening memory. She considers herself "very independent," and lives alone; however, the development of her new symptoms is causing her some distress, as she often forgets to pay her bills. A detailed review of systems reveals no other symptoms, except for mild urinary incontinence. She has hypertension controlled with a beta-blocker and type 2 diabetes mellitus controlled with diet. She does not use tobacco, alcohol or drugs. Her blood pressure is 130/90 mmHg, pulse is 72/min, temperature is 36.7°C (98°F) and respirations are 14/min. Lungs are clear to auscultation and percussion. A grade 2/6, systolic ejection murmur is heard. Abdominal examination shows no tenderness or masses. Neurological examination shows broad-based, shuffling gait and a right-sided carotid bruit. Complete blood count and serum chemistry panel are within normal limits MRI shows enlarged ventricles. What is the most likely diagnosis?

233) A 12-year-old boy is brought to the clinic for a routine health maintenance exam. He has no complaints, but mentions some spots on his back, which he noticed during his physical education class. He does not know how long they have been there. He denies any allergies. He remembers having a few seizures some years ago, which have not recurred since. He does not take any medication. The physical examination reveals several white spots and nodules measuring 2x3 cm on his back. There are freckles on his face and axilla. Closer examination reveals some nodules on his iris. What is the concerning complication that this boy is prone to?

234) A 25-year-old woman comes to the office and complains of intermittent dizziness and an unsteady gait for the last few days. Her symptoms worsen with exercise. Her past medical history is significant for tingling and numbness of her right foot that lasted 3-4 days (1 year ago), and visual loss in her right eye which spontaneously resolved (3 years ago). She is currently nursing her 2-month-old baby. Her obstetrical history was uncomplicated. Her neurological examination shows right hyperactive deep tendon reflexes. On attempted left gaze, her left eye abducts and exhibits horizontal jerk nystagmus, but her right eye remains stationary. When she attempts to look to the right, her right eye abducts and exhibits horizontal jerk nystagmus, but her left eye remains stationary. The patient is able to converge both eyes together, without any associated nystagmus. The facial muscles show no signs of weakness. Where is the most likely site of this patient's lesion?

235) A 60-year-old male complains of recent onset gait imbalance and visual illusion of to-and-fro environmental motion. The symptoms are constant. He has no associated nausea or vomiting. His past medical history includes diabetes, hypertension, and chronic renal failure, and recent enterococcal endocarditis for which he is taking ampicillin and gentamicin. On physical examination, his temperature is 36.7°C (98°F), blood pressure is 120/76 mm Hg, pulse is 80/min, and respirations are 16/min. Neurologic examination shows 5/5 power and 2+ reflexes in all four extremities. Cranial nerve examination is normal. There is no nystagmus. Which of the following is the most likely cause of his current condition?

236) A 63-year-old accountant is brought to the emergency department after suddenly collapsing at his desk at work. He is unconscious upon arrival but regains consciousness within several minutes. His medical history is significant for stable angina, hypertension, and hypercholesterolemia. He has had no surgeries. His medications include atenolol, simvastatin, aspirin, and a multivitamin. Physical examination is remarkable for paralysis of the upper and lower extremities on the right side. Vibration and position sense are absent on the right side. When the flat of the right foot is stroked with a pen, the right great toe is up going and the other toes fan out. The patient's tongue deviates to the left upon protrusion. Given these findings, a lesion in which region of the brain is most likely?

237) A 60-year-old white male is brought to the physician's office for the evaluation of worsening confusion and memory loss for the past three weeks. His other complaints are muscle twitching and gait problems. He denies any fever, headache or urinary problems. He does not drink nor smoke. His pulse is 82/min, blood pressure is 130/76 mm Hg, and temperature is 37.1°C (98.7°F). He displays poor grooming and is disoriented. The pertinent physical findings are nystagmus and positive extensor plantar response bilaterally. The laboratory studies are as follows: Hematocrit 40%, WBC 6,000/microl, Platelets 160,000/microl. A non-contrast head CT scan is normal. The EEG shows periodic sharp waves. What is the most likely diagnosis of this patient?

238) A 70-year-old retired engineer is brought to the office by his son for a routine check-up. He believes that his son is too greedy and wants all his property. He is accusing his son of "kicking him out of the house to get all of his property." He has been getting more forgetful over the past few years. His younger sibling has the same problem. He has no significant past medical history, except a history of smoking for 6 years when he was young. His blood pressure is 138/78 mm Hg, pulse is 86/min, respirations are 14/min and temperature is 37.0°C (98.6°F). He cannot remember current events, such as the name of the current American president; however, he can still remember past political history. He is unable to concentrate, but is oriented to time, place and person. The neurological examination is nonfocal. CT scan reveals mild generalized atrophy. His HIV and RPR tests are negative. The serum electrolytes and thyroid function tests are normal. What is the most likely diagnosis of this patient?

239) A 54-year-old man comes to your office complaining of recurrent headaches. While observing his gait as part of your neurologic examination, you notice that he very prominently flexes his right hip and knee and his right foot slaps to the floor with each step. Which of the following is the most likely cause of this gait abnormality?

240) A 33-year-old female presents to the office for the evaluation of a one-week history of lightning-like pain on the left side of her face. The pain is very sharp and feels like a burn. An episode lasts for 10 seconds, occurs 10-20 times a day, and keeps her from sleeping, eating, or working. She denies any history of trauma; medication use or recent surgery Vital signs are within normal limits. What is the most likely diagnosis?

241) A 72-year-old woman complains of difficulty "finding the right word" when she is speaking. Her daughter notes that she also frequently complains that her neighbor is stealing her newspapers when this is not the case in actuality. Recently, the patient has been having difficulty balancing her check book as well. On physical examination, her blood pressure is 160/100 mmHg and her heart rate is 90/min. The exam is otherwise unremarkable. Over the course of the next three years, the patient develops a severe memory deficit, and suffers from poor sleep, slowness of movement, shuffling gait and urinary incontinence. Which of the following is the most likely diagnosis?

242) A 32-year-old man presents to your office with blurred vision in his right eye. He denies any pain, ocular discharge, or gritting sensation. Physical examination findings include anisocoria, right-sided ciliary injection, mild ptosis, and impaired right eye adduction. Fluorescein examination reveals a large geographic corneal staining defect. Dysfunction of which of the following nerves is most likely responsible for this patient's impaired corneal sensation?