OBJECTIVETo report two de novo acute myeloid leukemia (AML) patients with t(11;22)(q23;q11.2) and summarize the clinical and biological characteristics.

METHODSBone marrow cells morphology, immunophenotype, chromosome karyotype, fluorescence in situ hybridization (FISH), PCR and gene sequencing were performed. Clinical manifestation and routine laboratory tests were analyzed.

RESULTSThe patients were diagnosed as AML-M₂ and AML-M₅ by morphology and immunophenotype results. Both patients carried t(11;22)(q23; q11.2) and one of them carried an additional chromosome abnormality. MLL-SEPTIN5 fusion transcript was identified in two patients by RT-PCR and sequencing. The two patients got hematologic complete remission after induction chemotherapy with daunorubicin, homoharringtonine, and cytarabine (DHA) or daunorubicin and cytarabine (DA). One of them relapsed and died during consolidation therapy with intermediate-dose cytarabine.

CONCLUSIONLeukemia with t(11;22)(q23;q11.2) chromosome translocation met the clinical and laboratory manifestations of AML. The MLL-SEPTIN5 fusion transcript was the distinctively biological etiology. Patients with t(11;22)(q23;q11.2) were vulnerable to relapse after conventional chemotherapy and had poor prognosis. Allogeneic hematopoietic stem cell transplantation should be recommended as early as possible.