NBME Pathology 2 — Questions and Answers
Question 1: A 55-year-old man with chronic alcoholism presents with jaundice and hepatomegaly. Liver biopsy shows hepatocyte swelling with intracytoplasmic eosinophilic inclusions. What are these inclusions?
- Mallory-Denk bodies (Correct answer)
- Russell bodies
- Lewy bodies
- Negri bodies
Correct answer: Mallory-Denk bodies
Mallory-Denk bodies are aggregates of intermediate filaments (cytokeratins) found in hepatocytes in alcoholic liver disease.
Question 2: A 30-year-old woman presents with recurrent DVTs, spontaneous abortions, and a positive lupus anticoagulant test. Which pathological mechanism underlies her condition?
- Autoantibodies against phospholipid-binding proteins (Correct answer)
- Complement-mediated endothelial injury
- Factor V Leiden mutation
- Protein C deficiency
Correct answer: Autoantibodies against phospholipid-binding proteins
Antiphospholipid syndrome is caused by autoantibodies (anti-beta2-glycoprotein I, anticardiolipin) that promote thrombosis and pregnancy loss.
Question 3: A neonate develops respiratory distress shortly after birth. Chest X-ray shows ground-glass opacities bilaterally. Autopsy reveals hyaline membranes lining alveolar ducts. What is the primary deficiency?
- Surfactant (dipalmitoylphosphatidylcholine) (Correct answer)
- Alpha-1 antitrypsin
- Lysyl oxidase
- Fibronectin
Correct answer: Surfactant (dipalmitoylphosphatidylcholine)
Neonatal respiratory distress syndrome results from surfactant deficiency in premature infants, leading to alveolar collapse and hyaline membrane formation.
Question 4: A 40-year-old woman with systemic lupus erythematosus has a kidney biopsy showing 'wire loop' lesions. What is deposited in these capillary walls?
- IgG and C3 immune complexes (Correct answer)
- IgA deposits
- Anti-GBM antibodies
- Amyloid fibrils
Correct answer: IgG and C3 immune complexes
Wire loop lesions in lupus nephritis (class IV) represent subendothelial immune complex deposits causing marked capillary wall thickening.
Question 5: A 65-year-old man undergoes colectomy for colorectal carcinoma. Pathology shows a tumor that is confined to the muscularis propria with 2 positive regional lymph nodes. What is this lesion's TNM stage?
- T2 N1 M0 (Stage III) (Correct answer)
- T1 N0 M0 (Stage I)
- T3 N0 M0 (Stage II)
- T2 N0 M0 (Stage II)
Correct answer: T2 N1 M0 (Stage III)
T2 indicates invasion into but not through the muscularis propria; N1 indicates 1-3 positive regional nodes; M0 = no distant metastasis = Stage III.
Question 6: A 50-year-old woman with rheumatoid arthritis develops amyloidosis affecting the kidneys. Which amyloid protein is deposited in reactive (secondary) amyloidosis?
- AA (serum amyloid A-derived) (Correct answer)
- AL (immunoglobulin light chain)
- ATTR (transthyretin)
- Abeta2M (beta-2 microglobulin)
Correct answer: AA (serum amyloid A-derived)
Secondary (reactive) amyloidosis deposits AA protein, derived from the acute-phase reactant serum amyloid A, in response to chronic inflammatory conditions.
Question 7: A 20-year-old man has a testicular mass. Serum AFP is markedly elevated. Histology shows embryoid bodies and Schiller-Duval bodies. What is the diagnosis?
- Yolk sac tumor (endodermal sinus tumor) (Correct answer)
- Teratoma
- Choriocarcinoma
- Seminoma
Correct answer: Yolk sac tumor (endodermal sinus tumor)
Yolk sac tumors are the most common testicular tumor in infants and young children, characterized by Schiller-Duval bodies and elevated AFP.
NBME Pathology 2
A 55-year-old man with chronic alcoholism presents with jaundice and hepatomegaly.
Liver biopsy shows hepatocyte swelling with intracytoplasmic eosinophilic inclusions.
What are these inclusions?