De novo acute myelogenous leukemia with trilineage myelodysplasia associated with t(8;21)(q22;q22)

We describe a rare case of de novo acute myelogenous leukemia with trilinea ge myelodysplasia (AML/TMDS) associated with t(8;21)(q22;q22). The patient was admitted to our hospital with leukocytopenia. AML/TMDS was diagnosed by excess myeloblasts and morphological findings of bone marrow. The karyotyp e revealed 45, X, -Y, t(8;21)(q22;q22) in 17 of 20 analyzed mitoses, and al so AML1/MTG8 transcripts were detected by the reverse transcription polymer ase chain reaction (RT-PCR) method, The patient achieved a complete remissi on with a combination chemotherapy of daunorubicin, cytarabine, and prednis olone, This case suggests that t(8;21)(q22;q22) may participate in the path ogenesis of AML/TMDS, although this type is usually found as one of the chr omosomal abnormalities in de novo acute myelogenous leukemia (AML) with mat uration.