A 41-year-old male was admitted to Iwaki Kyoritsu General Hospital because of right cranial nerves (VII, IX, X, XI, XII) palsy caused by right suboccipital tumor. The white cell count in the peripheral blood was 7,100/μl containing 12% blast cells. NAP rate was 83% and score was 216. Chromosomal analysis revealed Ph1 abnormality. Using various monoclonal antibodies, the blast cells in the peripheral blood were determined as megakaryoblasts, positive for CDw 41: P2, CDw 41: J 15, CDw 42: AN 51, Plt-1 and KOR-P77. Histological examination of bone marrow revealed megakaryocytic proliferation and moderate replacement by fibrosis. Based on these findings, he was diagnosed as chronic myelogenous leukemia with megakaryocytic transformation without preceding chronic phase. He was treated with irradiation and chemotherapy, but it was difficult to get a complete remission. Seven months after admission, CD11b: MO1, CD13: MY7 and CD14: MY4 positive leukemic cells abruptly increased in the peripheral blood and he died of cerebral bleeding.
This is probably the first case of chronic myelogenous leukemia with megakaryocytic transformation “without chronic phase”.
