Bone and joint involvement in primary amyloidosis.

Primary amyloidosis is an interesting clinical entity in which amyloid is deposited in various organs, particularly mesodermderived tissues such as heart, skeletal muscle, skin, connective tissue and bone. A case with multiple lytic bone lesions is presented. Comparison to previous similar cases is made with attention being directed to the typical distribution of lesions about large joints with associated soft-tissue prominence and increase in the articular space. The differentiating radiologic features are compared to those of rheumatoid arthritis, hyperparathyroidism, and lytic metastatic lesions, with particular attention being given to the osteolytic lesions of plasmacytomas associated with multiple myeloma.