Histology USMLE Step 1 Practice Question
A 28-year-old man with Crohn disease presents with abdominal pain and diarrhea. Vital signs: BP 118/76, HR 88, RR 16, Temp 37.8°C, SpO2 98%. Colonoscopy with biopsy of inflamed terminal ileum shows transmural inflammation, crypt distortion, and noncaseating granulomas across multiple bowel wall layers. CRP is elevated at 8.2 mg/dL. Rectal bleeding is absent. Which histologic feature most reliably distinguishes this condition from ulcerative colitis?
Answer choices
- AContinuous inflammation limited to the mucosa and submucosa
- BSurface ulceration with pseudopolyp formation
- CCrypt abscesses with neutrophilic infiltration
- DTransmural inflammation with noncaseating granulomasCorrect answer
- ELoss of goblet cells and mucin depletion
- FCobblestone mucosal surface with deep linear fissuring ulcers
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