Multiple myeloma: clinical review and diagnostic imaging

Multiple myeloma (MM) is a malignant clonal neoplasm of plasma cells of B-lymphocyte origin that commonly results in overproduction of large amounts of monoclonal immunoglobulins. Important advances in the therapeutic management of this disease in the past decade have resulted in higher rates of durable complete remission, prolonged event-free survival, and improved overall survival. Clearer understanding of the effects of abnormal plasma cells on bone has led to therapeutic approaches that help prevent vertebral body fractures. Current imaging technologies and, in particular, survey marrow studies with magnetic resonance (MR) imaging have improved detection of the extent and location of disease in MM patients. In newly diagnosed cases, MR surveys of the axial skeleton accurately demonstrate the extent of disease-diffuse or focal involvement-and the presence of associated compression fractures and cord compression. After treatment, MR images show the effects of treatment and the presence of residual disease. Multiple sites of focal bone lesions detected on MR studies allow a more appropriate choice of biopsy site than the usual random iliac marrow biopsy. Use of MR to determine biopsy sites and computed tomographic guidance for biopsy performance have increased the safety and accuracy of sampling. These biopsies have resulted in increased identification of cytogenetic abnormalities, particularly the presence of chromosome 13 deletion, which is a grave prognostic indicator in MM.