2nd Endocrine USMLE

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?

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?

A 6-year-old boy is brought to his pediatrician for a routine check-up. He has not been seen by a physician for the past 3 years. Recently, he has developed some patchy areas of hair loss on his scalp. The mother also notes he has had many colds over the past year. She says he has developed normally, although he started walking later than her other two children. On physical examination his wrists appear enlarged, and he has bowing of the forearms and legs. X-ray of the boy’s legs is shown in the image. Laboratory tests show a calcium level of 7.1 mg/dL, phosphate of 1.8 mg/dL, and intact parathyroid hormone of 130 pg/mL (normal: 10–65 pg/mL). Vitamin D level is normal. Treatment with vitamin D does not correct the patient’s hypocalcemia. Which of the following disorders best explains this patient’s findings?

A 28-year-old woman presents to her gynecologist for her annual examination. She mentions that she and her husband have been trying to conceive for 9 months without success and that her menstrual cycles have become irregular. Her gynecologist suggests that she and her husband continue to try to conceive and that the woman return in 3 months for some laboratory studies if she still has not become pregnant. In the interim, a routine visit to the ophthalmologist reveals bitemporal hemianopsia. Which of the following is the most likely cause of this woman’s infertility?

Your patient is a 48-year-old Hispanic male with a 4-year history of diabetes mellitus type 2. He is currently utilizing NPH insulin/Regular insulin 40/20 units prior to breakfast and 20/10 units prior to supper. His supper time has become variable due to a new job and ranges from 5 to 8 PM. In reviewing his glucose diary, you note some very low readings (40-60 mg/dL) during the past few weeks at 3 AM. When he awakens to urinate, he feels sweaty or jittery so has been checking a fingerstick blood glucose. Morning glucose levels following these episodes are always higher (200- 250) than his average fasting glucose level (120-150). Which change in his insulin regimen is most likely to resolve this patient’s early AM hypoglycemic episodes?

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 mm Hg. On neck examination there is diffuse enlargement of the thyroid and it is exquisitely tender to even mild palpation. Laboratory tests show a total triiodothyronine 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?

A 32-year-old G2P1 woman at 16 weeks’ gestation presents to her obstetrician complaining of fatigue, anxiety, and palpitations. She says she has been feeling warm, even in her air-conditioned home, and has been having three or four loose stools per day, as compared to one or two prior to her pregnancy. She has a temperature of 37.1°C (98.9°F), heart rate of 105/min, and blood pressure of 128/76 mm Hg. Neck examination reveals mild diffuse enlargement of the thyroid gland with no lymphadenopathy. Relevant laboratory findings include a total triiodothyronine level of 400 ng/dL, free thyroxine of 6.8 ng/dL, and thyroid-stimulating hormone of 0.01 μU/mL (normal: 0.4–4 μU/L). Results of a thyroid- stimulating hormone-receptor antibody test are positive. Which of the following is the most appropriate therapy for this patient?

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?

A 50-year-old obese female is taking oral hypoglycemic agents. While being treated for an upper respiratory infection, she develops lethargy and is brought to the emergency room. Neurological examination is nonfocal; she does not have neck rigidity. Laboratory results are as follows: Na: 134 mEq/L K: 4.0 mEq/L HCO3: 25 mEq/L Glucose: 900 mg/dL BUN: 84 mg/dL Creatinine: 3.0 mg/dL HgA1c: 6.8% BP: 120/80 lying down, 105/65 sitting Which of the following is the most likely cause of this patient’s coma?

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?

A 13-year-old boy is brought to the pediatrician by his mother because of increasing body hair. Several months earlier he had been diagnosed with 17α-hydroxylase deficiency and treated with hydrocortisone. Physical examination reveals an overweight boy with a moderate amount of both chest and genital hair, and some facial hair growth. His physical examination is otherwise unremarkable. Which of the following is the best treatment for this patient?

A 72-year-old man with atrial fibrillation presents with complaints of fatigue and feeling cold. He also notes constipation and dry skin. His daughter states he has seemed more forgetful over the past several months. His temperature is 37.3°C (99.1°F), heart rate is 48/min, and blood pressure is 130/82 mm Hg. Cardiac examination shows bradycardia but normal rhythm, and normal S1 and S2 with no murmurs; the lungs are clear to auscultation bilaterally and the abdomen is soft and nontender. The patient’s extremities are cool and puffy with dry, coarse skin. Laboratory studies show a thyroid-stimulating hormone level of 32 μU/L, free thyroxine of 0.3 ng/dL, and total tri-iodothyronine of 30 ng/dL. What medication is the patient likely taking for his atrial fibrillation?

A 49-year-old woman presents to her physician’s office with a long-standing history of polydipsia, polyuria, central obesity, and hyperlipidemia. She is currently taking metformin, a sulfonylurea, and an angiotensin-converting enzyme (ACE) inhibitor. ACE inhibitors are most beneficial in preventing or slowing the progression of which of the following diabetic complications?

A 42-year-old woman presents to her physician with complaints of fever (38.2°C [100.8°F]) and mild-to-moderate anterior neck pain. On examination the physician finds her to be tachycardic and sweating, and to have an exquisitely tender thyroid gland. Her blood work shows a depressed thyroid-stimulating hormone level and increased free thyroxine. Which of the following is the most appropriate treatment at this time?

A 45-year-old G2P2 female presents for annual examination. She reports regular menstrual cycles lasting 3 to 5 days. She exercises 5 times per week and reports no difficulty sleeping. Her weight is stable 140 lbs and she is 5 ft 8 in tall. Physical examination is unremarkable. Laboratory studies are normal with the exception of a TSH value of 6.6 mU/L (normal 0.4-4.0 mU/L). Which of the following represents the best option for management of this patient’s elevated TSH?

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 1cm 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?

An obese 18-year-old woman is brought to the emergency department by her mother, who noted that she had been lethargic all day, and suffered a brief, seizure-like episode. One month earlier, the patient had been started on medication for type 2 DM. Lactic acid levels are normal. Which of the following medications most likely played a role in the patient’s current presentation?

A 75-year-old woman is brought to the emergency department after being found unresponsive at her home. She was last spoken to by her daughter on the phone 24 hours earlier, at which time she complained of chills, lethargy, and weakness. The woman has had a heart at- tack in the past, she has high blood pressure, and she had a total thyroidectomy performed a decade ago for cancer. The daughter had re- turned from several months out of town, and is unsure if the patient was taking her medications. Her temperature is 34.9°C (94.9°F), pulse is 48/min, blood pressure is 110/65 mm Hg, oxygen saturation is 99% on 100% oxygen, and glucose is 85 mg/dL. On examination the patient is unresponsive, obese, and edematous with periorbital edema. Her cardiac and pulmonary examinations are normal. CT of the head reveals no signs of trauma or increased intracranial pressure, and ECG demonstrates no acute ischemic changes. Blood is drawn for laboratory testing. Which of the following is most appropriate for treating the patient’s mental status change?

A family brings their 82-year-old grandmother to the emergency room stating that they cannot care for her anymore. They tell you, “She has just been getting sicker and sicker.” Now she stays in bed and won’t eat because of stomach pain. She has diarrhea most of the time and can barely make it to the bathroom because of her weakness. Her symptoms have been worsening over the past year, but she has refused to see a doctor. The patient denies symptoms of depression. Blood pressure is 90/54 with the patient supine; it drops to 76/40 when she stands. Heart and lungs are normal. Skin examination reveals a bronze coloring to the elbows and palmar creases. What laboratory abnormality would you expect to find in this patient?

A 14-year-old boy presents at the pediatric clinic for a routine check-up. The patient had developed end-stage renal disease over the previous 2 years, and was successfully treated with a renal transplant 6 months prior. Since his operation, he has developed purple striae on his back and arms, central obesity, and an increasingly round face. During the subsequent blood analysis, which of the following results would be most likely?

A 64-year-old man presents to the emergency department after a motor vehicle crash and receives a CT of the abdomen that shows a finding of a unilateral mass in the left adrenal gland. He is unharmed from the accident, feels well, and has never smoked. His blood pressure is 155/90 mm Hg, deep tendon reflexes are 3/4, and muscle strength is 4/5. Laboratory studies show: Na+: 150 mEq/L K+: 3.0 mEq/L Cl−: 105 mEq/L HCO −: 36 mEq/L Plasma renin activity is also decreased. Which of the following is most likely to be increased?

A 28-year-old patient with known Addison’s dis- ease presents with abdominal pain and is hypotensive to a systolic pressure of 88 mm Hg. He has a 2-week history of progressively worse nonproductive dry cough, sore throat, malaise, and headache. He has not checked his temperature at home but complains of constant chills. Which of the following is the best initial management?

A generally healthy 74-year-old woman who recently moved into the area visits the physician’s office for her first well-visit. She states that her previous doctor had been treating her with propylthiouracil (PTU) for subclinical hyperthyroidism, but that her prescription ran out several months ago. Laboratory studies reveal that her free thyroxine and triiodothyronine levels are normal, but her thyroid-stimulating hormone is depressed. PTU therapy is most important in this patient to prevent the development of which disorder?

A 58-year-old woman presents to her physician because of neck discomfort and difficulty swallowing. She first began to have difficulty with swallowing solids 2 years ago, but the problem is getting progressively worse. She denies hemoptysis, hematemesis, abdominal pain, or change in bowel habits. She is a nonsmoker and past medical history is significant only for mild hypertension. Her temperature is 36.9°C (98.4°F), heart rate is 72/min, and blood pressure is 132/78 mm Hg. She has an asymmetrically enlarged thyroid gland that is particularly firm on the right, with poorly palpable borders. Laboratory evaluation reveals a free thyroxine level of 4.1 ng/dL and thyroid-stimulating hormone of 5μU/mL. Based on the results of a radioisotope scan and a fine needle aspiration biopsy, the physician decides to perform surgery. For which of the following is the patient at increased risk postoperatively?

A 48-year-old high school teacher with no prior medical history presents to his primary care physician after feeling extremely fatigued for >1 month. Previously an avid runner, he has recently experienced dyspnea on moderate exertion. Although he denies vomiting, he admits to intermittent episodes of diarrhea. His blood pressure is 73/37 mm Hg and he is afebrile. On physical examination his skin is warm and erythematous, and his jugular venous pressure is elevated. Cardiac examination reveals a systolic murmur near the right border of the sternum that is accentuated with inspiration. Which of the following is most consistent with these findings?

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?

You recently evaluated a 28-year-old woman who presented with complaints of shakiness and heat intolerance. The patient plans to have children and is currently using no contraception. On examination you noted tachycardia with an HR of 102, a fine tremor, a diffuse goiter, and proptosis. You now have the laboratory results and note a TSH < 0.001, elevated total T4 of 17.8, and increased T3 uptake. Radionuclide uptake by the thyroid gland is elevated. You tell her that she has Graves’ disease. What is the best treatment plan for this patient?

A 56-year-old woman presents to the outpatient clinic for a routine visit. On physical examination a 1-cm nodule is palpated in her thyroid. Her physical examination is otherwise unremarkable. Her heart rate is 70/min and regular, blood pressure is 126/82 mm Hg, and temperature is 36.7°C (98.0°F). Which of the following is a poor prognostic indicator for the thyroid nodule?

A 52-year-old African-American woman with type 2 diabetes mellitus (DM) presents to her physician’s office and states that she has been feeling lousy in the morning. She notes that she reliably checks her blood glucose levels, and is frustrated at the fact that she often has a blood sugar level in the 120s at night, followed by a level in the 170s to 180s the following morning. The patient’s primary care physician increased her nightly dose of neutral protamine Hagedorn insulin 1 month ago, but her morning glucose levels have only become more elevated. She has recently begun to limit her carbohydrate intake at night, with no effect. This patient’s morning hyperglycemia might most likely be alleviated by which of the following?

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 mm Hg, 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?

A 50-year-old female is evaluated for hypertension. Her blood pressure is 130/98. She complains of polyuria and mild muscle weakness. She is on no blood pressure medication. On physical examination, the PMI is displaced to the sixth intercostal space. There is no sign of congestive heart failure and no edema. Laboratory values are as follows: Na+: 147 mEq/dL K +: 2.3 mEq/dL Cl−: 112 mEq/dL HCO3: 27 mEq/dL The patient denies the use of diuretics or over-the-counter agents to decrease fluid retention or promote weight loss. She does not eat licorice. Which of the following tests is most useful in establishing a diagnosis?

A 36-year-old female complains of inability to lose weight despite low calorie diet and daily exercise. She has also noticed that she is cold intolerant. She is wearing a jacket even though it is summer. She also reports constipation and hair loss. These symptoms have been worsening over the past 2 to 3 months. An elevated TSH and low total and free T4 confirm your suspicion of hypothyroidism. You suspect the etiology of this patient’s hypothyroidism to be autoimmune thyroiditis. What is the best test to confirm the diagnosis of autoimmune thyroiditis?

A 61-year-old obese man with a history of chronic alcohol abuse is diagnosed with type 2 DM. In addition to diet modification and exercise, his physician recommends he begin therapy with a hyperglycemic agent. Several days after starting therapy, his wife comes home from work and finds him sitting on the couch staring into space and breathing rapidly. When she speaks to him, she finds he is quite confused, and immediately takes him to the emergency department. Arterial blood gas analysis shows: pH: 7.2 HCO −: 19 mEq/L Partial carbon dioxide pressure: 32 mm Hg Partial oxygen pressure: 80 mm Hg Lactate: 6 mmol/L Which of the following drugs is most likely responsible for this patient’s symptoms?