Amyloid Light Chain Amyloidosis Involving the Heart and Temporal Arteries, Mimicking Giant Cell Arteritis.

BACKGROUND: Amyloid light chain (AL) amyloidosis is an uncommon multisystem condition. We report a globally unique case of a patient with AL amyloidosis affecting the heart and temporal arteries. CASE SUMMARY: A 74-year-old man presented with jaw claudication and temporal artery tenderness and was treated for giant cell arteritis. He was later admitted to the cardiology service with elevated cardiac biomarkers with echocardiographic features of an infiltrative cardiomyopathy. Cardiac magnetic resonance suggested amyloidosis, and diagnosis of AL amyloidosis was confirmed via temporal artery biopsy. Treatment with bortezomib, cyclophosphamide, and dexamethasone yielded an appropriate clinical response. DISCUSSION: Although AL amyloidosis is known to be associated with cardiac involvement with isolated cases of large vessel involvement, this is the first global case to our knowledge of AL amyloid affecting the temporal arteries and cardiac function simultaneously. TAKE-HOME MESSAGES: AL amyloidosis is a multisystem disorder. Cardiac phenotyping should be mandatory.