USMLE Step 1 · Pathology and Microbiology

Pathology

36 practice questions, each with the answer and an explanation.

Practise Pathology now

Random questions from this topic, one at a time. You see the answer and the explanation straight after each one.

All 36 questions

  1. A 40-year-old man with a long history of reflux has a distal esophagus lined with columnar epithelium and goblet cells. What is the complication he is at risk for?
  2. A 55-year-old woman has a mole that has changed in color and size. Biopsy shows atypical melanocytes invading the dermis. Which feature best predicts prognosis?
  3. An 8-year-old boy has bowed legs, widened wrists and a rachitic rosary. Which vitamin deficiency is most likely?
  4. A 25-year-old man has painless cervical lymphadenopathy and Reed-Sternberg cells with owl-eye nuclei on biopsy. What is the diagnosis?
  5. A 60-year-old man has a swollen, red first metatarsophalangeal joint. Joint fluid shows negatively birefringent needle-shaped crystals. What is the diagnosis?
  6. A 58-year-old man has crushing chest pain for 2 hours. ECG shows ST elevation in leads II, III and aVF. Which coronary artery is most likely occluded?
  7. A 28-year-old woman has episodes of weakness and optic neuritis. MRI shows periventricular plaques. Which cells are damaged in the central nervous system?
  8. A 45-year-old woman has a thyroid mass with amyloid deposits and elevated calcitonin. Which syndrome is associated?
  9. A 65-year-old man dies 5 days after a myocardial infarction. Autopsy shows a soft, yellow, necrotic myocardium with neutrophil infiltration. What is the most likely complication at this stage?
  10. A 55-year-old man has painless jaundice, weight loss and a palpable nontender gallbladder. What is the most likely cause?
  11. A 4-year-old child has fatigue, bruising and a lymphoblast-filled marrow with TdT-positive cells. What is the most likely diagnosis?
  12. A 70-year-old man has dyspnea and pleural thickening. He worked in shipbuilding. Which tumor is associated?
  13. A 45-year-old woman has a 5-cm breast mass. Biopsy shows malignant cells in a single-file pattern with targetoid growth around ducts. Which tumor is most likely?
  14. A 22-year-old woman has tremor, Kayser-Fleischer rings and liver disease. What is the underlying defect?
  15. A 25-year-old woman has abdominal pain and diarrhea. Colonoscopy shows skip lesions and cobblestone mucosa, and biopsy shows noncaseating granulomas. What is the diagnosis?
  16. A 50-year-old man has fatigue, weight loss and a spleen that extends below the umbilicus. His white count is 150,000 with all stages of granulocytes and a Philadelphia chromosome. What is the diagnosi…
  17. A 48-year-old woman has pruritus and fatigue. Labs show elevated alkaline phosphatase and positive antimitochondrial antibodies. What is the diagnosis?
  18. A 60-year-old smoker has a central lung mass, hypercalcemia and keratin pearls on biopsy. What is the diagnosis?
  19. A 50-year-old alcoholic has severe epigastric pain radiating to the back and an elevated serum lipase. What is the most likely diagnosis?
  20. A 55-year-old man has a central lung mass and hyponatremia with inappropriately concentrated urine. Biopsy shows small blue cells. What is the paraneoplastic cause?
  21. A 30-year-old woman has a thyroid nodule with orphan Annie eye nuclei and psammoma bodies. What is the diagnosis?
  22. A 5-year-old child has generalized edema, heavy proteinuria and normal glomeruli on light microscopy. What is the diagnosis?
  23. A 30-year-old man has cirrhosis, diabetes and bronze skin. Which gene is mutated?
  24. A 25-year-old woman has a malar rash, arthritis and proteinuria. Which antibody is most specific for her disease?
  25. A 55-year-old woman has morning stiffness lasting over an hour and symmetric swelling of the metacarpophalangeal joints. Which finding is most specific?
  26. A 30-year-old woman has flank pain and hematuria. Ultrasound shows bilateral enlarged kidneys with cysts. Which gene is commonly mutated?
  27. A 70-year-old man has progressive memory loss. Autopsy shows neurofibrillary tangles and extracellular plaques. What is the main component of the plaques?
  28. A 60-year-old man has resting tremor, bradykinesia and rigidity. Which pathologic finding is expected?
  29. A 55-year-old man has hematuria and a renal mass. Biopsy shows clear cells with abundant glycogen. Which genetic abnormality is typical?
  30. A 25-year-old man has hemoptysis and hematuria. Kidney biopsy shows linear IgG deposits along the glomerular basement membrane. What is the diagnosis?
  31. A 55-year-old man with long-standing diabetes has nodular glomerulosclerosis. What is this lesion called?
  32. A 68-year-old woman has a pelvic fracture after minor trauma. DEXA shows a T-score of -3.0. Which lab finding is expected in primary osteoporosis?
  33. A 35-year-old woman has bloody diarrhea, and colonoscopy shows continuous mucosal inflammation from the rectum with crypt abscesses. What is the diagnosis?
  34. A 7-year-old boy has periorbital edema and cola-colored urine 2 weeks after a sore throat. Which finding is expected?
  35. A 10-year-old boy from Africa has a jaw mass with a starry-sky appearance on histology and a t(8;14) translocation. What is the diagnosis?
  36. A 40-year-old woman has dry eyes, dry mouth and parotid enlargement. Which antibodies are most likely present?

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