Multiple Myeloma and Acute Myelomonocytic Leukemia

Abstract

A rapidly progressive acute myelomonocytic leukemia developed in four patients who had received prolonged courses of melphalan, ranging from 30 to 57 months. Three patients were being treated for typical multiple myeloma (anemia, elevated sedimentation rate, monoclonal serum peak, Bence-Jones protein in the urine, lytic bone lesions and increased numbers of myeloma cells in the marrow), and one for a plasma-cell dyscrasia, with systemic amyloidosis of five years' duration. Because of the remote likelihood of chance association of acute leukemia and multiple myeloma, the known effect of alkylating agents on deoxyribonucleic acid, the fact that the leukemia was myelomonocytic, and the long period of treatment with melphalan, a possible etiologic role of melphalan therapy in the development of acute leukemia is suggested.