Department of Internal Medicine, Kochi Municipal Central Hospital.
A 72-year-old man with refractory anemia with an excess of blasts developed overt leukemia with leukothrombocytosis. Hematological and physical findings closely resembled those of an accelerated or blastic phase of chronic myelocytic leukemia. The cytogenetic anomaly of i(17q) was observed during the course. The present case is suggestive of the diversities of myelodysplastic syndromes (MDS), including relationships between MDS and myeloproliferative disorders (MPD) and acute leukemia.