C-Biopsy of Artery
◦ Temporal artery biopsy (TAB) is currently the gold standard method for the diagnosis of giant cell arteritis (GCA), with a specificity of 98% to 100% when histopathology demonstrates active necrotizing arteritis, characterized by a predominance of mononuclear cell infiltrates or a granulomatous process with multinucleated giant cells. Other features include narrowing and occlusion of the arterial lumen, intimal proliferation, rupture of the internal elastic layer, and lumen thrombosis.
◦ However TAB has a sensitivity of 77% and its false-negative rate ranges from 9% to 61%.
◦ False negatives may be due to the timing of biopsy, the length of the specimen, or the presence of segmental “skipping lesions” (observed in 12%‒28% of cases).
◦ It is also estimated that 25% of TAB for GCA are reported as “healed arteritis”, defined as fibrosis, attenuation and/or neovascularization of the media, irregular intimal proliferation, multifocal to complete loss of internal elastic lamina, adventitial fibrosis, and absence of ongoing chronic medial inflammation. The presence of “healed arteritis” is more often associated with prior history of polymyalgia rheumatica and longer corticosteroid use before TAB.
📸 Histopathological findings in biopsy-proven giant cell arteritis:
(A) Temporal artery with narrowed lumen, atrophic media, interrupted elastic lamina, and granulomatous inflammation consistent with the diagnosis of giant cell arteritis (H&E, x50).
(B) Typical area of granulomatous inflammation with multiple giant cells (black arrows) in the interrupted elastic lamina (H&E, x400).
(C) Similar findings in another temporal artery biopsy with interrupted elastic lamina (black arrow), granulomatous inflammation, and giant cell formation (H&E, x200).
(D) A clearer area of interrupted elastic lamina (red arrowhead) after special staining (Elastin, x200).
*Source: Alkatan, Hind M et al. “Giant cell temporal arteritis: a clinicopathological study with emphasis on unnecessary biopsy.” Frontiers in Ophthalmology vol. 3 1327420. 2023
🔗
doi.org/10.3389/fopht.2023.1…