USMLE Questions Bank

A 17-year-old girl comes to the office because of a 3-month history of daily moderate epigastric pain that is more severe after meals. Three weeks ago, she had watery diarrhea for 2 days, which resolved spontaneously. She has not had vomiting. She has no history of serious illness and takes no medications. Vital signs are within normal limits. Examination, including abdominal examination, shows no abnormalities.

Which of the following is most likely to confirm the diagnosis?
(A) CT scan of the abdomen
(B) Endoscopy
(C) Examination of the stool for ova and parasites
(D) Stool culture
(E) Upper gastrointestinal series

The answer is in the first comment.

In a sample of 100 individuals, the mean leukocyte count is 7500/mm3, with a standard deviation of 1000/mm3. If the leukocyte counts in this population follow a normal (gaussian) distribution, approximately 50% of individuals will have which of the following total leukocyte counts?
(A) 5500–9500/mm3
(B) 8500/mm3
(C) 6500–8500/mm3
(D) 9500/mm3

The answer is in the first comment.

A 53-year-old man is admitted to the hospital for treatment of acute pancreatitis. Temperature is 37.8°C (100.0°F), pulse is 90/min, respirations are 16/min, and blood pressure is 160/90 mm Hg. Oxygen saturation is 94% on room air. There is tenderness and voluntary guarding in the epigastrium with hypoactive bowel sounds. Physical examination otherwise shows no abnormalities. Pneumatic compression devices are in place on both lower extremities. Results of laboratory studies show a leukocyte count of 18,700/mm3, serum amylase concentration of 540 U/L, and serum lipase concentration of 500 U/L (N

A surgical intensive care unit observes that the number of days that patients have central venous catheters in place and the number of bloodstream infections have been increasing. A multidisciplinary team from the unit would like to decrease the number of days that central venous catheters are in place in order to improve performance in this area.

Which of the following is the most appropriate next step?
(A) Ask clinical providers in the unit to identify what they believe to be the most common factors leading to nonremoval of central venous catheters
(B) Change all central venous catheters every 5 days
(C) Place stickers on all intensive care unit doors reminding staff to reassess the need for a central line
(D) Plan a randomized controlled trial to test the effects of a reminder to reassess the need for a central line on a daily goals sheet implemented during rounds

The answer is in the first comment.

An 18-year-old woman with sickle cell disease is brought to the emergency department by her parents because of a 2hour history of severe abdominal pain and nausea. Her parents say that she had a cheeseburger, milk shake, and chocolate bar for lunch. Her temperature is 37°C (98.6°F). Physical examination shows tenderness over the right upper quadrant of the abdomen, radiating to the right shoulder. Ultrasonography of the right upper quadrant of the abdomen shows gallstones.

Which of the following is the most likely underlying cause of this patient's current condition?
(A) Decreased hepatic secretion of lecithin
(B) Decreased reabsorption of bile salts
(C) High ratio of cholesterol to bile acids in bile
(D) Infestation with parasites secreting β-glucuronidase
(E) Overload of unconjugated bilirubin

The answer is in the first comment.

A 39-year-old woman comes to the office because of a 1-year history of progressively worsening shortness of breath. She had been generally healthy and says that initially the shortness of breath occurred only after strenuous exercise; however, she now becomes fatigued and short of breath after walking two to three blocks. During the past 2 weeks, she has noted a rapid heart rate and light-headedness. She has not had chest pain, lower extremity edema, orthopnea, or any nocturnal symptoms. Medical history is remarkable for Graves disease, which was diagnosed 4 years ago and treated with radioactive iodine. Current medications include levothyroxine, a daily multivitamin, and an oral contraceptive. She does not smoke ci******es or drink alcoholic beverages. She is 168 cm (5 ft 6 in) tall and weighs 57 kg (125 lb); BMI is 20 kg/m2. Temperature is 37.0°C (98.6°F), pulse is 120/min and irregular, respirations are 16/min, and blood pressure is 110/85 mm Hg. Lungs are clear to auscultation. Cardiac examination discloses a rapid rate, a palpable parasternal lift, a normal S1, and a widely split, prominent S2. There is a grade 2/6 systolic murmur heard best over the second intercostal space. Examination of the lower extremities discloses trace edema of both feet. The remainder of the physical examination discloses no abnormalities.

Results of laboratory studies are shown: Serum Blood
Na+ 140 mEq/L
K+ 3.4 mEq/L
Cl− 100 mEq/L
HCO3 − 25 mEq/L
Glucose 130 mg/dL
TSH 0.58 μU/mL
Hemoglobin 13.0 g/dL
Platelet count 155,000/mm3

ECG shows atrial fibrillation with a ventricular rate of 140/min and right axis deviation. Chest x-ray shows clear lung fields, no effusion, and prominent pulmonary arteries.

Which of the following is the most appropriate additional diagnostic study?
(A) CT scan of the chest
(B) Echocardiography
(C) Perfusion lung scan
(D) Pulmonary function testing
(E) Ultrasonography of the thyroid

The answer is in the first comment.

A 2-year-old girl is brought to the office by her parents for a well-child examination. She was adopted 2 months ago. She has no history of serious illness and receives no medications. Vital signs are within normal limits. Examination shows no abnormalities. After the examination, the parents ask when they should tell their daughter about the adoption.

Which of the following is the most appropriate advice regarding the best time to tell this patient?
(A) After she turns 18 years of age
(B) As early as possible, even if she cannot process the whole experience
(C) Once the seal on the adoption records has been lifted
(D) Right before she is enrolled in kindergarten
(E) When she learns that she is not biologically related to her parents

The answer is in the first comment.

A 3-year-old boy is brought to the office because of a 2-day history of bulging of his left eye. He says his eye hurts. He has no history of major medical illness or recent trauma to the area, and he receives no medications. Vital signs are within normal limits. Physical examination shows exophthalmos of the left eye. MRI of the brain shows a 2-cm mass involving the ocular muscles of the left eye. A biopsy specimen of the mass shows malignant cells, some of which have striations.

Which of the following is the most likely diagnosis?
(A) Neuroblastoma
(B) Pheochromocytoma
(C) Retinoblastoma
(D) Rhabdomyosarcoma
(E) Thyroid cancer

The answer is in the first comment.