Basic USMLE VTH2

15) A 10-year-old boy is admitted to the hospital because of bleeding. Pertinent laboratory findings include a platelet count of 50,000/μL, prothrombin time (PT) of 15 seconds (control 11.5 seconds), activated partial thromboplastin time (aPTT) of 51 seconds (control 36 seconds), thrombin time (TT) of 13.7 seconds (control 10.5 seconds), and factor VIII level of 14% (normal 38%-178%). Which of the following is the most likely cause of his bleeding?

17) A 10-year-old boy presents with fever, headache, photophobia, and neck discomfort in the middle of summer. He is alert and oriented, but has neck pain with flexion and extension of the head. His fundi are normal, and there are no focal neurologic findings or skin changes. A lumbar puncture reveals normal protein and glucose with a cell count of 240/mL (90% lymphocytes). Which of the following is the most likely causative organism?

23) A 12-year-old African American boy is brought to the office due to a 2-day history of high-grade fever and chills. He was apparently well before the onset of fever. He has no bone pain. He has sickle cell disease and has had 4 hospitalizations for painful crises and one episode of osteomyelitis. His blood pressure is 90/60 mm Hg, pulse is 100/min, respirations are 22/min and temperature is 38.9 C (102F). He appears drowsy. His laboratory report shows a total WBC count of 16,000/mm3 with 12% bands and Hb of 9.0 g/dl. Which of the following is the most likely cause of this patient's condition?

40) A 14-year-old girl is brought to the physician's office because of irregular menstrual periods. She had her menarche at age 13, and since then her periods have been irregular with the cycles varying from 3 to 6 weeks. She has no other symptoms. Physical examination is unremarkable. She has age appropriate secondary sexual characteristics. A urine pregnancy test is negative. Serum prolactin and thyroid stimulating hormone levels are normal. Administration of micronized oral progesterone results in withdrawal bleeding in 3 days. Which of the following most likely explains her irregular periods?

50) A 16-year-old African American male with sickle cell anemia presents complaining of a 1-week history of exertional dyspnea, fatigue, and generalized weakness. He denies fevers, chills, night sweats, or cough. His only medication is oxycodone for chronic pain. On physical examination, he weighs 68 kg (150 lbs) and is 168cm (66 in) tall His temperature is 36.7C (98F), blood pressure is 120/70 mm Hg, pulse is 76/min, and respirations are 18/min. All organ systems appear normal Laboratory studies show: Hematocrit 20%, Mean corpuscular volume 110 fl, Reticulocyte count 1.0%. Which of the following is the most likely mechanism underlying these findings?

53) A 16-year-old boy is brought into the emergency department by his friends. He is semicomatose, with a pulse of 60/min and respirations of 6-8/min. His pupils are constricted. Which of the following will most likely be revealed on a urine toxicology screen?

55) A 16-year-old boy who is the backup quarterback for the local high school team is in your office complaining of worsening acne. For the last few months he has noted more acne and more oily hair. On his examination, you note gynecomastia and small testicular volume. He is SMR 5. Which of the following drugs of abuse is the likely explanation for all of his findings?

58) A 16-year-old College student presents to the physician's office because of a generalized malaise, sore throat and fever for the past 2 to 3 days. She is given amoxicillin prescription. Twenty-four hours later, she develops a polymorphous rash over her entire body. She has taken amoxicillin in the past for sinus disease and never had any problem. What is the most likely organism that is responsible for her symptoms?

74) A 19-year-old college student presents with a testicular mass, and after treatment he returns for regular follow-up visits. Which of the following is the most useful serum marker for detecting recurrent disease after treatment of nonseminomatous testicular cancer?

78) A 19-year-old man sustains multiple injuries in a high-speed automobile collision. There is a pneumothorax on the left, for which he has a chest tube placed. Over the next several days, a large amount of air drains continuously through the tube (a large "air leak"), and daily chest x-rays show that his collapsed left lung is not expanding. The patient is not on a respirator. Which of the following is the most likely cause of these findings?

83) A 19-year-old woman was traveling in a rural area of South America. She returned 3 weeks ago and, over the past few days, has gradually developed lower abdominal pain and diarrhea. Now the symptoms are much worse with 10 stools a day consisting mostly of mucus and blood. She is afebrile, the abdomen is tender in left lower quadrant, and the remaining examination is normal. Her stool is mostly comprised of blood and mucus. Which of the following is the most likely causative organism?

86) A 2-day-old male infant is jaundiced. He was born at term from an uncomplicated pregnancy, and was normal at birth. He otherwise appears healthy and is feeding well. Vital signs are stable. Physical examination shows jaundice. There is no organomegaly. Laboratory investigations show: Hemoglobin 17.0 g/L, MCV 88 fl, Platelets 220,000/mm3, Leukocyte count 4,500/mm3, Total bilirubin 7.5 mg/dL, Indirect bilirubin 6.0 mg/dL. What is the most likely cause of this patient's jaundice?

90) A 2-week-old infant presents with hepatosplenomegaly and a thick, purulent, bloody nasal discharge. Coppery, oval, maculopapular skin lesions are present in an acral distribution. The neurologic examination is normal, including head circumference. Which of the following is the most likely cause of this congenital infection?

94) A 2-year-old boy is brought to the office by his parents due to severe diarrhea since yesterday. He has had approximately 20 episodes of non-bloody, non-mucoid stool passage in the last twenty hours, and one episode of bilious vomiting. He is also feeding less than usual. He is febrile, tachycardic and moderately dehydrated. What is the most likely cause of his presentation?

107) A 20-year-old G0 and her partner, a 20-year-old man, present for counseling for sexual dysfunction. Prior to their relationship, neither had been sexually active. Both deny any medical problems. In medical experience, which type of male or female sexual dysfunction has the lowest cure rate?

122) A 22-year-old college student went to the health clinic complaining of a fever over the last 5 days, fatigue, myalgias, and a bout of vomiting and diarrhea. The clinic doctor diagnosed him with acute gastroenteritis and told him to drink more fluids. Three days later, the student presents to the ED complaining of substernal chest pain that is constant. He also feels short of breath. His temperature is 100.9°F, HR is 119 beats per minute, BP is 120/75 mmHg, and RR is 18 breaths per minute. An ECG is performed revealing sinus tachycardia. A chest radiograph is unremarkable. Laboratory tests are normal except for slightly elevated WBCs. Which of the following is the most common cause of this patient’s diagnosis?

134) A 23-year-old male is found at the scene of a motor vehicle accident with bilateral lower extremity fractures. You also note extensive abdominal bruising and scalp lacerations. At the scene, the patient's blood pressure is 80/60 mmHg and his heart rate is 120/min. He is given 2 liters of IV fluids wide open. On the way to the hospital he becomes progressively drowsy, and he develops progressive weakness on the right side of his body. This patient is also likely to show deficits in the functioning of which of the following nerves?

136) A 23-year-old man comes to the psychiatrist with a chief complaint of a depressed mood. He is very anxious and obviously uncomfortable in the physician’s office. Which of the following actions should be used to help develop rapport with this patient?

141) A 23-year-old woman presents to the ED complaining of pain with urination. She has no other complaints. Her symptoms started 3 week ago. During this time, she has been to the clinic twice, with negative urine cultures each time. Her condition has not improved with antibiotic therapy with sulfonamides or quinolones. Physical examination is normal. Wet mount showed epithelial cells. Which of the following organisms is most likely responsible for the patient’s symptoms?

151) A 24-year-old male experiences syncope while shovelling snow. He regained consciousness within one minute. He has been having some shortness of breath and chest pains recently, mostly related to exercise. He denies any illicit drug use. His temperature is 37.2°C (98.9°F), and blood pressure is 126/76 mmHg, pulse is 76/min and respirations are 14/min. Physical examination shows a well-built male in no apparent distress. Lungs are clear. A crescendo-decrescendo systolic murmur is heard along the left sternal border without carotid radiation. Chest X-ray is normal. Which of the following is the most likely cause of his syncopal episode?

158) A 25-year-old African American woman presents with a photo distributed skin rash and arthralgias. She is found to have low-range proteinuria and abnormal urinary sediment. Renal biopsy findings are consistent with focal proliferative glomerulonephritis. Her complete blood count shows: Erythrocyte count 3.2 mln/mm3, Platelets 60,000/mm3, Leukocyte count 2,500/mm3. Which of the following is the most likely cause of these hematologic findings?

165) A 25-year-old woman comes into the office with a three-month history of weight loss, irritability, insomnia, and palpitations. Her past medical history is insignificant. She is not taking any current medications and denies drug abuse. Her blood pressure is 155/70 mmHg and heart rate is 110/min. Physical examination reveals lid retraction, fine tremor of the hands, and increased neck circumference. The most probable cause of hypertension in this patient is?

175) A 26-year-old G1P0 woman at 12 weeks gestation presents to her obstetrician for her first visit. Her pregnancy thus far has been notable only for some mild nausea and vomiting that lasted throughout her first trimester. She reports feeling overly tired lately and very weak. Her past medical history is significant for pernicious anemia. On physical examination she is an anxious-appearing, thin woman. Her blood pressure is 130/85 mmHg, heart rate is 115/ min, and respiratory rate is 18/min. Fetal heart tones are present at 135/min. The uterine fundus is at 12 cm. The woman has a diffuse, non- tender goiter, a resting tremor, and poor global muscle strength. Which is the most likely mechanism underlying this woman’s condition?

184) A 27-year-old man presents to the emergency department with unremitting nose bleeding. He reports having a similar bleeding episode one year ago that was stopped in the ER. He works as a computer programmer and has a sedentary lifestyle. He drinks alcohol on social occasions but does not smoke or use illicit substances. On physical examination, there are several ruby-colored papules on his lips that blanch partially with pressure. Digital clubbing is also present. His abdomen is soft and non-tender. The liver span is 8 cm and the spleen is not palpable. Laboratory findings are: Hematocrit 60%, WBC count 8,000/mm3, Platelets 180,000/mm3. Which of the following is most likely responsible for this patient's increased hematocrit?

196) A 28-year-old primigravida is admitted to the hospital at 10weeks gestation. Her right leg is swollen. Her BMI is 30 Kg/m2. Her temperature is 36.7°C (98.2°F), respirations are 12/min and pulse is 96/min. Her ABG shows the following: pH 7.49, PaCO2 50 mm Hg, HCO3- 44 mEq/L. Which of the following is the most likely cause of her abnormal arterial blood gas?

203) A 29-year-old Caucasian primigravida patient is 20 weeks pregnant with twins. She found out today on her routine ultrasound for fetal anatomy that she is carrying two boys. In this patient’s case, which of the following statements about twinning is true?

229) A 3-year-old-boy ingests 40 of his older sister's chewable vitamin tablets, as well as 3 tablets of 250 mg of acetaminophen. The ingredients in the multivitamin tablets are as follows: Vitamin A 3000 IU, Thiamine 1 mg, Vitamin C 75 mg, Vitamin B6 1 mg, Vitamin D 400 IU, Iron 12 mg, Fluoride 1 mg. The child is brought to the emergency department in no acute distress. Which of the following complications may occur if appropriate therapy is not undertaken?

251) A 32-year-old male complains of progressive weakness and exertional dyspnea. His past medical history is significant for a knife injury to the right thigh two months ago. He has been arrested several times for robbery. He consumes alcohol regularly, and smokes crack occasionally. His younger brother died of cystic fibrosis. His blood pressure is 160/60 mmHg, and heart rate is 100/min. His extremities are warm and flushed. Carotid upstroke is brisk. The point of maximal impulse is displaced to the left, and a soft, holosystolic murmur is heard over the cardiac apex. The murmur does not change with the Valsalva maneuver. Which of the following is the most likely cause of this patient's symptoms?

279) A 34-year-old man rushes into the ER complaining of severe substernal chest pain that began abruptly 30 minutes ago. He says that he also feels as though his heart 'is racing,' but denies any shortness of breath, cough or fever. He has never experienced pain like this before. His past medical history is significant for an appendectomy one year ago. The patient reports that his father died at age 64 due to "some heart problem" and his mother died of ovarian cancer. On physical examination, the patient is agitated and sweating profusely. His pulse is 110/min, blood pressure is160/100 mmHg, and respirations are 14/min. Physical examination is normal except for dilated pupils and a small amount of blood at the external nares. EKG shows ST elevations in leads v1-v4. What is the most likely explanation for his symptoms?

280) A 34-year-old obese Caucasian female complains of periodic visual obscurations. She has episodes during which she "goes blind" for several seconds when standing up or stooping forward abruptly. She also describes frequent morning headaches over the last two months for which she has had to take ibuprofen or aspirin almost every morning. She takes no other medications. Past medical history is insignificant aside from one uncomplicated vaginal delivery. She denies use of alcohol, tobacco, or illicit drugs. She is afebrile with a blood pressure of 138/88 mmHg and pulse of 93/min. Visual field testing shows enlarged blind spots. There are no other significant findings on neurologic examination. Which of the following is the most likely cause of this patient's symptoms?

290) A 35-year-old woman who has recently emigrated from Asia presents to the emergency room with acute onset of dyspnea. She denies any cough, chest pain, or fever. She has a history of rheumatic heart disease as a teen. On examination, she has an irregular pulse of 97/min, blood pressure of 125/75 mmHg and temperature of 37.2°C (98.9°F). The first heart sound is loud and a mid-diastolic rumble is heard at the apex. Crackles are present in both lung fields. ECG shows an irregularly, irregular heart rhythm and the absence of 'P' waves. Which of the following is the most likely cause of this patient's abnormal heart rhythm?

294) A 36-year-old white male is brought to the emergency department because of dyspnea, tachypnea, crampy pain and paresthesias in his extremities. He gives an unclear history about how he "rapidly ascended to a height of 10,000 feet” His pulse is 70/min, blood pressure is 120/80 mmHg, temperature is 36.7°C (98.5°F) and respirations are 24/min. The significant physical finding on examination is carpopedal spasm. At this point, the suspected diagnosis is acute respiratory alkalosis secondary to hyperventilation. Which of the following is true regarding this patient's serum calcium level?

304) A 38-year-old G4P3 at 33 weeks gestation is noted to have a fundal height of 29 cm on routine obstetrical visit. An ultrasound is performed by the maternal-fetal medicine specialist. The estimated fetal weight is determined to be in the fifth percentile for the estimated gestational age. The biparietal diameter and abdominal circumference are concordant in size. Which of the following is associated with symmetric growth restriction?

318) A 4-week-old boy is brought to clinic by his mother because of a 1 day history of labored breathing. His birth was uneventful and immunizations have been up to date. His mother reports that the patient developed conjunctivitis on the fourth day of life. On physical examination, he is breathing rapidly at 40 breaths per minute and is afebrile. His chest reveals bilateral inspiratory crackles and a slight wheeze. On chest x-ray, bilateral pneumonia is evident. The leukocyte count is elevated at 15,000 with 40% eosinophils. Which of the following is the most likely pathogen causing the patient's symptoms?

324) A 4-year-old male is brought to the physician with fever and headache. His symptoms began two days ago with low-grade fever, cough, and congestion. Last night, he developed a temperature of 102 F (38.9 C) and became fussy and less active. Today, he is crying and complaining of a headache. His parents report that he has vomited twice today. In the office, his temperature is 102.5 F (39 C), pulse is 110/min, and respiratory rate is 20/min. On examination, he is irritable and shows signs of photophobia. His oropharynx is erythematous. Nuchal rigidity is present and when the neck is flexed, the patient flexes his lower extremities. The remainder of the physical examination is normal. Lumbar puncture is performed and the results are shown below. CSF: Glucose 60 mg/dL, Protein 80 mg/dL, RBC 10/mm3, WBC 100/mm3, Neutrophils 10%, Lymphocytes 70%, Monocytes 20%, Gram stain negative. Which of the following organisms is most likely responsible for this patient's presentation?

335) A 42-year-old morbidly obese man is being evaluated for poor sleep. He complains of frequent awakenings due to a choking sensation and says that the resulting tiredness severely limits his physical activity. He also complains of chronic leg swelling. He denies cigarette, alcohol, or drug use. On physical examination, his blood pressure is 160/100 mmHg and his heart rate is 110/min. Which of the following additional findings is most likely to be present in this patient?

338) A 42-year-old, right-handed man has had a history of progressive speech difficulties and right hemiparesis for 5 months. He has had progressively severe headaches for the past 2 months, which are worse in the mornings. At the time of admission, he is confused and vomiting, and has blurred vision, papilledema, and diplopia. Shortly thereafter, his blood pressure increases to 190/110 mm Hg, and he develops bradycardia. Which of the following is most likely the significance of the hypertension and the bradycardia?

339) A 43-year-old Caucasian female has a long history of polyarthritis. She also complains of fatigue, low-grade fever, weakness and recent weight loss. Her current medications are methotrexate, naproxen and ranitidine. Physical examination reveals deformed hand joints and a soft, tender mass palpated in the right popliteal fossa. The latter finding is best explained by:

405) A 52-year-old female presents with a rash over her face for the past few weeks. She also complains of recent-onset difficulty with rising from a seated position and climbing stairs. On examination, you notice a dusky malar rash and a violaceous periorbital edema. Her vital signs are within normal limits. Examination shows symmetric proximal muscle weakness in legs. This patient's condition is most often associated with which of the following?

412) A 53-year-old homosexual man comes to the ER with shortness of breath and dry cough over the past week. You note that he was hospitalized for Candida esophagitis one month ago, but left against medical advice. On physical examination, his blood pressure is 120/70 mmHg, heart rate is 120/min and regular, oxygen saturation is 89% on 2L/min of oxygen by nasal cannula, and temperature is 38.3°C (101°F). There are extensive white plaques over the oral mucosa and there is a soft 2/6 systolic murmur over the cardiac apex. Lung auscultation is remarkable for faint bilateral crackles. Which of the following is most likely responsible?

413) A 53-year-old male presents to your office with a two-day history of right calf pain and swelling. He describes the pain as constant and states that it is exacerbated by knee flexion. He has a history of past IV drug abuse, endocarditis, and stroke. He is currently wheelchair-bound secondary to stroke-related left-sided hemiparesis. On physical examination, his blood pressure is 140/90 mmHg and his heart rate is 100/min. There is no jugular venous distention or hepato-jugular reflux. His chest is clear to auscultation but his abdomen is enlarged with shifting dullness and a fluid wave, suggestive of ascites. His liver is palpable 3 cm below the right costal margin. His spleen is also palpable. On examination of his lower extremities, you note right-sided calf swelling and tenderness. Which of the following is the most likely cause of this patient's ascites?

430) A 55-year-old homeless man presents to the emergency room complaining of muscle cramps and perioral numbing. The patient looks malnourished. He says that he consumed a lot of alcohol recently. His past medical history is significant for chronic and recurrent abdominal pain for which he was advised to quit drinking alcohol. His temperature is 36.7°C (98°F), blood pressure is 110/65 mmHg, pulse is 80/min, and respirations are 18/min. The laboratory values are: Hemoglobin 7.2 g/dl, MCV 105 fl, Leukocyte count 9,000/cmm, Platelets 200,000/cmm, ESR 20 mm/hr, Serum sodium 145 mEq/L, Serum potassium 4.0 mEq/L, Serum calcium 6.8 mg/dl, Serum phosphorus 2.5 mg/dl. What is the most probable cause of hypocalcemia observed in this patient?

433) A 55-year-old woman has been hospitalized because of recurrent pancreatitis, ARDS, prolonged ileus, and need for parenteral nutrition. She demonstrates weakness, lassitude, orthostatic hypotension, nausea, and fever. Which of the following abnormalities is most likely to explain these symptoms?

446) A 57-year-old Caucasian female is diagnosed with deep venous thrombosis of the right leg that was confirmed with Doppler ultrasonography. She was diagnosed with pneumonia and empyema one week earlier, and treated with chest tube, antibiotics and bed rest. On her 6th day of anticoagulation therapy, she develops right hemiparesis and slight motor aphasia. The laboratory findings are: Red blood cells 4.3 million/mm3, Hemoglobin 14.00 g/dL, White blood cells 7,000/cmm, Platelets 50,000/cmm, APTT 60 sec (N < 25-40 sec), Fibrin degradation products negative. The emergency head CT scan does not reveal blood in the subarachnoid space or brain parenchyma. Which of the following is the most probable cause of this patient's condition?

457) A 59-year-old man comes to the physician because of dysuria, urinary urgency, and frequency. He also complains of hematuria, nocturia, decreased force of stream, and a feeling of incomplete voiding. These symptoms have been present for more than a month. For the past few days he has been experiencing dull, non-radiating suprapubic pain. He has also been having low-grade fever and malaise for the past couple of days. He has been taking analgesics for osteoarthritis of his right knee for more than 10 years. He has a 40-pack-years history of cigarette smoking and does not use alcohol or drugs. Rectal examination shows a smooth, firm enlargement of the prostate without induration or asymmetry. Neurological examination shows no abnormalities. Urinalysis shows hematuria with isomorphic red blood cells. Laboratory studies show a serum creatinine of 1.5 mg/dl, and a PSA of 2 ng/ml. Which of the following is the most likely explanation for this patient's symptoms?

459) A 6-month-old infant has been exclusively fed a commercially available infant formula. Upon introduction of fruit juices, however, the child develops jaundice, hepatomegaly, vomiting, lethargy, irritability, and seizures. Tests for urine-reducing substances are positive. Which of the following is likely to explain this child’s condition?

463) A 6-year-old African-American child is brought in by his father for complaints of easy fatigability and pallor. These symptoms occurred after the son was treated with "some medication" for a recent diarrhea. Physical examination is normal except for pallor and multiple petechiae. Laboratory values are as follows: Hb 8.0 g/dL, WBC 12,000/cmm, Platelets 50,000/cmm, Blood glucose 118 mg/dL, Serum Na 135 mEq/L, Serum K 5.3 mEq/L, Chloride 110 mEq/L, Bicarbonate 18 mEq/L, BUN 38 mg/dL, Serum creatinine 2.5 mg/dL, Total bilirubin 3 mg/dL, Direct bilirubin 0.5 mg/dL, PT 12 seconds, APTT 30 seconds, LDH 900 IU/L, Reticulocyte count 6%. A peripheral blood smear reveals giant platelets and multiple schistocytes. What is the most likely underlying pathophysiology for this boy's pallor?

469) A 6-year-old boy is seen in the office for evaluation of polyuria. Further questioning reveals several months of headache with occasional emesis. Your physical examination reveals a child who is less than 5% for weight. He has mild papilledema. His glucose is normal, and his first urine void specific gravity after a night without liquids is 1.005 g/mL. Which of the following might also be expected to be seen in this patient?

472) A 60-year-old Caucasian male is brought to the emergency department by his daughter due to a 2-day history of confusion and lethargy. According to his daughter, he had been complaining of fatigue, anorexia, polyuria and constipation for the last several weeks. He smokes two packs of cigarettes daily, and consumes alcohol occasionally. His blood pressure is 130/90 mmHg and heart rate is 90/min. Physical examination reveals a somnolent patient who is not oriented in time. His lab values are: Serum Na 140 mEq/L, Serum K 4.0 mEq/L, Serum chloride 100 mEq/L, Serum bicarbonate 22 mEq/L, Serum creatinine 1.6 mg/dl, Serum calcium 13.4 mg/dL, Serum phosphorus 2.2 mg/dL, Blood glucose 100 mg/dL, Alkaline phosphatase 80 U/L. Chest x-ray demonstrates a right middle lobe mass and perihilar adenopathy. What is the most probable cause of this patient's symptoms?

476) A 60-year-old male presents to the emergency room with the chief complaint of progressive exertional dyspnea and fatigue. He denies any chest pain, syncope, cough, or edema. He suffered an acute anterior wall myocardial infarction one month ago. Chest auscultation reveals bilateral crackles in his lower chest. Cardiac auscultation reveals a pansystolic murmur at the apex with radiation to the axilla. ECG shows previously present unchanged Q waves and a persistent ST segment elevation in the anterior leads. Based on these findings, what is the most likely underlying cause of his symptoms?