Histopathological examination of tissue obtained from a suspected tuberculous lesion of bone shows epithelioid cell granulomas with Langhans giant cells. Which additional finding provides the strongest support for tuberculosis rather than sarcoidosis?

• A Presence of multinucleate giant cells
• B Central caseous necrosis within the granulomas ✓
• C Surrounding lymphocytic infiltrate
• D Fibrosis at the periphery of the granulomas

Explanation

Caseating granulomatous inflammation with central amorphous necrosis is the histological hallmark of tuberculosis; sarcoidosis produces non-caseating 'naked' granulomas. Multinucleate giant cells, a rim of lymphocytes and peripheral fibrosis are shared features of chronic granulomatous inflammation of many causes, including sarcoidosis and fungal infection, so they cannot separate the two diagnoses. Definitive confirmation still requires demonstration of acid-fast bacilli by Ziehl-Neelsen stain or culture.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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