A 28-year-old Black woman has a dry cough and dyspnea. Chest radiograph shows symmetric bilateral hilar lymphadenopathy with fine reticulonodular opacities. Transbronchial biopsy reveals well-formed non-caseating granulomas composed of tightly clustered epithelioid macrophages. Which finding on additional workup best supports the diagnosis?

• A Elevated sweat chloride concentration
• B Positive c-ANCA by indirect immunofluorescence
• C Positive interferon gamma release assay
• D Elevated serum angiotensin converting enzyme level ✓

Explanation

The combination of bilateral hilar adenopathy, non-caseating granulomas without necrosis, and demographic profile is classic for sarcoidosis. Activated macrophages within granulomas express angiotensin converting enzyme, so elevated serum ACE supports the diagnosis, though it is neither specific nor used to monitor therapy alone. D positive IGRA suggests tuberculosis, where caseation is expected, killing option C. c-ANCA points to granulomatosis with polyangiitis.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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