Diffuse pigmented villonodular synovitis in association with Paget's disease of bone: report of a case.

A 73-year-old patient with Paget's disease of bone was found to have associated diffuse pigmented villonodular synovitis (PVNS) of the right knee joint. Paget's disease has been reported in association with bone sarcoma, benign giant-cell tumor of bone, myeloma and a single case of giant-cell tumor of tendon sheath. the tendency for Paget's disease to be associated with giant-cell-rich lesions of bone and joint, which includes PVNS, merits further investigation, particularly since the recent observation of intranuclear viral-like inclusions in the osteoclast of all patients with this disease.