Erosive arthritis in hereditary amyloidosis.

Nine patients from 2 distinct kindreds with familial amyloidosis had episodes of inflammatory arthritis and radiographic evidence of joint erosions. Histologic features from erosive lesions in both kindreds showed proliferation of synovium with erosive bone and cartilage change. No large amyloid deposits were seen. This study indicates that an erosive synovitis of unknown cause may be a feature of some forms of hereditary amyloidosis.