Sideroblastic Anemia in Multiple Myeloma: A Preleukemic Change

In a 10-yr observation period, 75 patients with multiple myeloma have been studied, and 55 of these were treated daily with low dose melphalan by mouth. Of these, four developed sideroblastic anemia, manifested by anemia, thrombocytopenia, aniso-poikilocytosis, and hypochromic stippled cells in the blood, and ringed sideroblasts in the bone marrow. In two patients, this complication occurred after more than 7 yr of therapy and at a time when there was no evidence of myeloma. In a third patient, it occurred when the myeloma relapsed, and in the fourth, myeloma was active but stable. The anemia did not respond to either folate or pyridoxine. In all four patients, acute myelomonoblastic leukemia developed within 6 mo after sideroblastic anemia had been detected. These observations suggest that sideroblastic anemia in myeloma is a preleukemic manifestation.