[Successful low-dose etoposide therapy for a case of myelofibrosis with chronic myelogenous leukemia megakaryocytic predominance type].

A 38-year-old woman presented with ear pain and vertigo. No hepatosplenomegaly or lymphadenopathy were found, but her platelet counts markedly rose to 414 x 10(4)/microliters with an increase of megakaryocytes in the bone marrow (859/microliters). Cytogenetic assay revealed positive Ph1 chromosome and rearrangement of the break point cluster region (bcr). Although platelet counts remained under 100 x 10(4)/microliters after the administration of carboquone, a high fever and pancytopenia appeared 31 months later. Bone marrow biopsy showed marked myelofibrosis which was improved by low dose etoposide. This case was thought to be Ph1 positive ET, but it was more compatible with CML megakaryocytic predominance type according to the newly proposed "Hannover criteria for myeloproliferative disorders" and cytogenetic assay.