[Chronic myelogenous leukemia with marked thrombocytosis--comparison with essential thrombocythemia with Ph1 in its megakaryokinetics].

A case of chronic myelogenous leukemia (CML) with marked thrombocytosis and its megakaryokinetics were reported. Patient was 57-year old woman who had a marked thrombocytosis (1,413 x 10(3)/microliters) and a bone marrow megakaryocytosis. Bone marrow karyotype demonstrated Ph1 chromosome in all cells examined. However, on physical examination, there was no splenomegaly. CBC showed no immature myeloid cells, and neutrophil alkaline phosphatase was elevated. These manifestations were consistent with so called essential thrombocythemia (ET) with Ph1 chromosome reported by Nissenblatt. To know the megakaryokinetics of this case, we examined the number of colony forming unit-megakaryocyte (CFU-M), platelet glycoprotein (PGP) IIb/IIIa positive cells, cytoplasmic area, and DNA content, comparing with those of normal subjects, CML, and ET. We found a marked increase of CFU-M and PGP IIb/IIIa positive cells, but in contrast, decreased DNA content and cytoplasmic area. This pattern of megakaryokinetics was consistent with that of CML. We conclude that ET with Ph1 chromosome may be a variant of CML rather than ET itself.