Multiple myeloma: recognition and management.

Multiple myeloma is the malignant proliferation of plasma cells involving more than 10 percent of the bone marrow. The multiple myeloma cell produces monoclonal immunoglobulins that may be identified on serum or urine protein electrophoresis. Bone pain related to multiple lytic lesions is the most common clinical presentation. However, up to 30 percent of patients are diagnosed incidentally while being evaluated for unrelated problems, and one third of patients are diagnosed after a pathologic fracture, commonly of the axial skeleton. Multiple myeloma must be differentiated from other causes of monoclonal gammopathy, including monoclonal gammopathy of undetermined significance, heavy chain disease, plasmacytoma and Waldenstrom macroglobulinemia. Chemotherapy with melphalan-prednisone is the standard treatment for multiple myeloma. Other treatment modalities include polychemotherapy and bone marrow transplantation. Only 50 to 60 percent of patients respond to therapy. The aggregate median survival for all stages of multiple myeloma is three years.