[Effectiveness of azacitidine in chronic myelomonocytic leukemia harboring del(20q) - a case report].

A 7 1-year-old man was admitted to our hospital with leukocytosis and anemia. Chronic myelomonocytic leukemia (CMML)harboring del(20q)was diagnosed by peripheral blood examination and bone marrow aspiration. The patient was subsequently treated with azacitidine, which resulted in rapid disappearance of monocytosis and resolved his dependency on red cell transfusion. With regard to the chromosomal abnormality, although del(20q)is estimated to be encountered in approximately 0.7-1.0% of all CMML cases, its significance in prognosis has not been fully analyzed. Hence, more such cases need to be evaluated to elucidate the therapeutic outcome of CMML involving del(20q). In addition, the Wilms tumor-1(WT 1)level in the patient gradually decreased after the initiation of azacitidine therapy. This phenomenon of WT1 decrease synchronizing with the patient's clinical improvement might reflect therapeutic efficacy with regard to the clinical course, as had been observed in acute myeloid leukemia and myelodysplastic syndrome.