AMYLOIDOMA OF BONE, A PLASMA-CELL PLASMACYTOID NEOPLASM - REPORT OF 3CASES AND REVIEW OF THE LITERATURE

Tumoral amyloidosis (amyloidoma) of bone is a rare condition character ized by the massive destructive deposition of AL amyloid in bones. We report three cases. The patients ranged in age from 45 to 78 years and had tumors located in the lumbar spine, scapula, and humeral head mea suring 6.5 to 18 cm. The radiologic diagnosis was chondrosarcoma in tw o cases. Microscopically, there were large, rounded deposits of amorph ous eosinophilic material surrounded by numerous giant cells and a spa rse lymphoplasmacytic infiltrate. The deposits proved to be composed o f AL amyloid showing potassium permanganate resistant congophilia. Imm unohistochemistry showed immunoglobulin IgG lambda, IgG kappa, and IgM lambda monoclonality of the plasma cell and (in one case) lymphoid in filtrate. The tumors were classified by morphology and immunohistochem istry as solitary plasmacytomas of bone (two cases) and plasmacytoid l ymphoma (one case). During the relatively short follow-up period, one patient progressed to symptomatic generalized amyloidosis and died, on e patient died of recurrent tumor, and one patient is alive with no ev idence of disease. An extensive review of the world literature showed 34 well-documented similar cases, occurring most often in the spine an d skull, causing neurologic symptoms, tending to occur in middle-aged men and frequently progressing to generalized disease. Most if not all AL amyloidomas of bone represent solitary plasmacytomas of bone or pl asmacytoid lymphomas.