Systemic amyloidosis with temporal artery involvement mimicking temporal arteritis.

A 77-year-old man presented with jaw claudication, arthralgias and myalgias, weight loss, marked fatigue, and thickened temporal arteries. No vasculitis was seen on the temporal artery biopsy specimen, but amyloidosis was suspected and confirmed with Congo red staining. Subsequent bone marrow biopsy revealed multiple myeloma. Although the patient initially was thought to have temporal arteritis, the results of temporal artery biopsy directed further investigations that led to the diagnosis of systemic amyloidosis. Systemic amyloidosis should be considered in the differential diagnosis when patients, especially men, present with clinical findings suggestive of temporal arteritis but without evidence of vasculitis in temporal artery biopsy specimens.