A 67-year-old man was admitted because of thrombocytopenia in May 1998. His white blood cell count was 4,900/microliter with 3.5% blasts. Laboratory findings were as follows: hemoglobin level, 10.1 g/dl; platelet count, 1.8 x 10(4)/microliter; ALT, 56 IU/l; LDH, 3,570 IU/l; IgG, 653 mg/dl; IgA, 64 mg/dl; IgM, 49 mg/dl; IgD, 674 mg/dl. Serum immunoelectrophoresis confirmed IgD lambda M-component. Bone marrow aspiration showed 79.2% myeloma cells expressing a mostly plasmablastic morphology. No mature plasma cells were found in the bone marrow. The patient received a continuous drip infusion of 20 mg/body cytarabine (Ara-C) and 50 mg/body etoposide (VP-16) for 7 days. No plasmablastic myeloma cells were detected, but 2.1% mature plasma cells were found in his bone marrow on day 20. On day 18 his platelet count exceeded 10.8 x 10(4)/microliter, and the serum IgD level fell to 210 mg/dl. Therapy consisting of melphalan, methylprednisolone and vincristine was started from day 23. No IgD lambda M-component was detectable by serum immunoelectrophoresis seven months after the diagnosis of multiple myeloma. The patient has been in complete remission as of April 2000.