[Megakaryoblastic transformation associated with disseminated intravascular coagulation in the course of polycythemia vera: a case report].

A 57-year-old male who had suffered from polycythemia vera (PV) and had been treated with pipobroman, carbazilquinon and busulfan for ten years presented with fever. CBC revealed anemia and thrombocytopenia without an increase of leukemic blasts (WBC, 7,700/microliters, RBC 294 x 10(4)/microliters, Hb 9.1 g/dl, Plt 1.5 x 10(4)/microliters). Bone marrow aspiration resulted in dry tap. Bone marrow biopsy showed hyperplastic marrow with fibrosis and no increase in leukemic blasts. Eleven days later the patient became leukemic and he died of DIC. Blast cells showed a high nucleo-cytoplasmic ratio, basophilic cytoplasm and cytoplasmic blebs. Cytochemical and immunophenotype analysis of the blast cells showed the following results; myeloperoxidase (-), chloroacetate esterase (-), Sudan black (-), acid phosphatase (+), acetate esterase (+), PAS (+), HLA-DR (+) and GPIIb/IIIa (+). Platelet peroxidase reaction on electron microscopy was positive in perinuclear spaces and endoplasmic reticulum. A diagnosis of megakaryoblastic transformation of PV was made. Although acute myelogenous leukemia has been shown to develop occasionally in the course of PV, acute megakaryoblastic leukemia with DIC following PV is a very rare condition.