Successful low-dose cytosine arabinoside treatment in a patient with acute leukemia from idiopathic myelofibrosis.

We report a 63-year-old male with acute leukemia developed from idiopathic myelofibrosis. Cytogenetic analysis revealed chromosomal abnormalities; 46,XY,t(3;21)(q21;q22) del(20q). Intensive chemotherapies [combination of adriamycine/vincristine/prednisolone, or idarubicine/cytosine arabinoside (Ara-C)] were unsuccessful. The patient was then treated with continuous intravenous low-dose Ara-C because of his poor physical condition and showed marked hematological improvement. Leukemic cells disappeared from the peripheral blood and the segmented neutrophil count recovered. The dysplastic morphology observed in the segmented neutrophils suggests that the recovery of the neutrophils has resulted mainly from the differentiation activity of Ara-C.