Cases have been reported in which there is production of J chain but no heavy or light chain. Clinical, hematologic, and radiologic findings are similar to those of standard myeloma. Bone lesions usually progress to multiple myeloma. Extraosseous lesions rarely spread and can be surgically excised.
Treatment is with aggressive chemotherapy.
MGUS is sometimes referred to as dysproteinemia without associated disease. Bone marrow biopsy and aspirate show a mild increase in plasma cells, but no mass lesion. WM is associated with ML, small lymphocytic type. Mast cells, while accompaning many lymphoproliferative disorders are especially numerous and characteristic of Waldenstrom's. The malignant cells secrete a monoclonal IgM protein which causes a macroglobulinemia.