[Long survival of a patient presented with blastic crisis of chronic myelomonocytic leukemia]

A 77-year-old man was diagnosed as having acute myelomonocytic leukemia (M4) with increased ringed sideroblasts in the bone marrow (BM) in October, 1979. Complete remission was achieved and ringed sideroblasts disappeared after two courses of CMP (cytarabine, 6-mercaptopurine, prednisolone) therapy. Following remission, there was no increase of blasts during the course of the disease, but monocytosis and dysmyelopoiesis persisted for about seven years. The monocytosis was controlled by 6-mercaptopurine. In June, 1986, however, monocytosis in peripheral blood (PB) and BM developed again, and there was severe pancytopenia and reappearance of ringed sideroblasts without increase of blasts. The patient died of pneumonia on September, 1986. Postmortem examination revealed hypercellular marrow with a few blasts, leukemic cell infiltration into spleen, liver and lymph nodes, ad lung cancer. His clinical and hematological features after remission of acute leukemia accorded with those of CMMoL. The dysmyelopoiesis observed in this case in not induced by anti-leukemic agents, but originated from the same clone as the initial AMMoL, and his disease was thought to be CMMoL converted from blastic crisis to chronic phase.