A 34-year-old man presents with chronic cough, low-grade fever, and night sweats. Chest imaging shows an upper lobe cavitary lesion. Biopsy of the lesion shows a granuloma whose center consists of amorphous, granular, eosinophilic debris completely devoid of cellular outlines, surrounded by epithelioid cells and Langhans giant cells. This pattern of necrosis is best described as:

• A Coagulative necrosis with ghost outlines of tubules
• B Caseous necrosis, a variant of coagulative necrosis ✓
• C Liquefactive necrosis due to lysosomal enzymes of neutrophils
• D Fat necrosis with saponification of parenchymal lipids

Explanation

Tuberculous granulomas show caseous necrosis: granular, friable, cheese-like debris with complete loss of cellular architecture, classified as a variant of coagulative necrosis unique to foci of tuberculous infection. Liquefactive necrosis (option C) produces a soft, creamy pus-like liquid from neutrophil lysosomal enzymes, as in abscesses and brain infarcts, not firm granular debris. The combination of epithelioid cells, Langhans giants, and amorphous granular center makes the diagnosis straightforward.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.