Multiple myeloma is a progressive neoplastic disease characterized by marrow plasma cell tumors and over production of an intact monoclonal immunoglobulin (Bence-Jones protein). The disease usually affects patients older than 40 years of age. Men and women are equally affected. The pelvis, ribs, spine and skull are most frequently involved. The predominant distribution of tumor cells within the bone marrow spaces is responsible for the destruction of bone and the major hematopoietic abnormalities including anemia, leukopenia, and thrombocytopenia. Plain radiographs may show diffuse osteoporosis or discrete osteolytic lesions due to replacement by expanding plasma cell tumors. Osteolytic lesions are often multiple and present as a solitary intramedullary mass. Osteoblastic lesions are rare, therefore bone scans are usually of little diagnostic value.

Patients often present with the discovery of a swelling, local tenderness, unrelenting pain or pathologic fractures. Myelomatous tumors characteristically are multiple and are confined mainly to the sites of red marrow: ribs, sternum, spine, clavicles, skull or extremities around the shoulder or pelvic girdles. The characteristic bone changes demonstrated radiographically are rounded punched?out areas. Periostial reactions and spontaneous new bone formation are rare, but may occur with successful therapy. Prognosis is dependent on extent of disease on diagnosis. About 60% of patients show objective improvement with radiation and chemotherdp~. Median survival is 2-3 years from diagnosis.