AL amyloidosis with temporal artery involvement simulates giant-cell arteritis.

Light-chain (AL) amyloidosis may present with features suggesting vasculitis, including giant-cell arteritis (GCA). We describe a case of an 80-year-old man, who initially presented with bilateral jaw claudication, bi-temporal headache and arthralgia, however a temporal-artery biopsy then revealed AL amyloidosis. A diagnosis of AL amyloidosis complicating multiple myelome simulates GCA and polymyalgia rheumatica was established. The patient was successfully treated with melphalan and dexamethasone: the free kappa light chains decreased, the patient's jaw claudication and headache disappeared. Then we discuss similarities between GCA and AL amyloidosis and potential confusion in diagnosis. We suggest that, in patients with clinical features of GCA without any temporal-artery typical findings, specimens are stained with Congo red, which then results in a different diagnosis and treatment.