A 30-year-old man with chronic abdominal pain, diarrhoea, low-grade evening fever and weight loss has an ileocaecal mass on CT. Biopsies are taken at colonoscopy. Which histological finding would most strongly favour intestinal tuberculosis over Crohn disease?

• A Crypt architectural distortion with Paneth cell metaplasia
• B Discrete non-caseating granulomas situated away from ulcers
• C Confluent caseating granulomas with acid-fast bacilli demonstrable on stain or culture ✓
• D Aphthous ulcers centred on lymphoid follicles

Explanation

Caseation and demonstration of Mycobacterium tuberculosis on stain, culture or PCR are the strongest discriminators for intestinal tuberculosis. Tuberculous granulomas are typically large, confluent and caseating, while Crohn granulomas are sparse, small, non-caseating and distant from ulcers. Options B and D describe Crohn-type pathology, and crypt distortion occurs in both conditions and cannot separate them.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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