Secondary amyloidosis associated with giant cell arteritis/polymyalgia rheumatica

Although giant cell arteritis (GCA) is characterized by chronic inflammation, secondary (AA) amyloidosis appears to be an exceptionally rare complication of this disorder. We describe an 84-year-old man with biopsy proven GCA and polymyalgia rheumatica (PMR) who was found at autopsy to have AA amyloid deposition in numerous organs, 9 years after his diagnosis of GCA. Persistent musculoskeletal symptoms, attributed to refractory PMR during the patient's life, were likely due to AA amyloidosis. This unrecognized complication of GCA/PMR confounded his therapy, leading to excessive treatment with corticosteroids and methotrexate. This case shows that the occurrence of AA amyloidosis should be considered in patients with "refractory PMR" developing after a period of treatment, and that autopsies play a vital role in enigmatic cases.