Essential thrombocythemia terminating in myelofibrosis and myeloblastic transformation

A 58-year-old man with essential thrombocythemia terminating in myelofibrosis and myeloblastic transformation is described. He was treated with busulfan and lived for 6 years and 6 months. At autopsy, significant osteomyelofibrosis was noted. Moreover, myeloblastic infiltration with proliferation of megakaryocytes and erythroblasts was seen in the bone marrow and spleen. In the lymph nodes, myeloid metaplasia was noted. The past reports on this disease terminating in myelofibrosis and/or blast transformation have been reviewed.