Osteolysis after silicone arthroplasty.

A young woman with a silicone lunate prosthesis for avascular necrosis developed painful lytic lesions in the distal ulna and the triquetrum. At reoperation, abundant reactive synovitis was found extending into those bone lesions. Histologic examination of the curetting samples revealed granulation tissue with histiocytes and many multinucleated giant cells containing refractile particles consistent with silicone. The authors report a giant cell lesion of the bone that radiographically and microscopically mimicked a neoplasm.