A 46-year-old man was admitted to the Kansai Medical University Hospital because of sever anemia. His laboratory data revealed severe refractory anemia with leucopenia. The first smear of bone marrow aspirate revealed a marked granulocytic hyperplasia with predominance of immature myeloid cells and pausity of erythroblastic elements, in which some of megakaryocytes could be found but most of them were dysplastic and micromegakaryocytic. NAP score was extremely low, and neither Auer rods, ringed sideroblasts nor chromosomal abnormarities could be identified. Hypergammaglobulinemia was observed 2 year after entry, serum immunoelectrophoresis gave a picture for monoclonal IgG (kappa) and Bence-Jones protein was proved in urine. He died of panmyelophthisis after long (100 months after entry) course of so-called smoldering leukemia. The autopsy findings revealed that present myeloid disorder would be classified as an atypical leukemia arising from the background of medullary stem cell disorder, namely a hemopoietic dysplasia designated as refractory anemia with an excess of myeloblasts in the bone marrow (Dreyfus), and that the repeated transfusions induced a secondary hemochromatosis and might evoke a plasma cell dyscrasia following lymphoid stem cell disorder.
