Giant cell arteritis (temporal arteritis) affects large and medium vessels in elderly patients. The characteristic histological finding on temporal artery biopsy in active disease is:

• A Neutrophilic vascular infiltration with fibrinoid necrosis (leukocytoclastic vasculitis pattern)
• B Eosinophil-rich infiltrates in adventitia and media (Churg-Strauss pattern)
• C Transmural granulomatous inflammation with multinucleated giant cells at the internal elastic lamina, lymphoplasmacytic adventitial infiltrate, and intimal thickening ✓
• D Non-necrotizing fibrous intimal plaque without inflammation

Explanation

Giant cell arteritis (GCA) shows granulomatous inflammation centered on the internal elastic lamina (IEL), which appears fragmented/destroyed. Multinucleated giant cells cluster near IEL remnants. The media shows CD4+ Th1-driven granulomatous inflammation with macrophages and giant cells; the adventitia shows lymphoplasmacytic infiltrate. Intimal hyperplasia causes luminal stenosis. Skip lesions occur so negative biopsy does not exclude diagnosis. GCA is distinguished from polyarteritis nodosa (necrotizing, no granulomas) and EGPA (eosinophil-rich).

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.