Which artery is the primary site affected in giant cell arteritis?

• A. Temporal artery
• B. Aorta
• C. Renal artery
• D. Pulmonary artery

Answer: (A)

Giant cell arteritis is a granulomatous large-vessel vasculitis that most often involves arteries in the head, with the temporal artery being the classic primary site. This predilection matters because the temporal artery is a superficial, easily accessible branch of the external carotid, and its inflammation produces the hallmark cranial symptoms: unilateral temporal headache, scalp tenderness, and often jaw claudication, with vision loss from ischemia if the disease extends or optic arteries are affected. Pathologically, you see granulomatous inflammation with multinucleated giant cells and destruction of the internal elastic lamina, leading to intimal thickening and luminal narrowing. While larger vessels like the aorta can be involved in some patients, and other arteries can be affected, the temporal artery epitomizes the typical site of involvement and is the most useful site for diagnostic biopsy in classic cases.