[Therapy-related acute myelogenous leukemia (AML-M6) with add(11) (q23) and del(20) (q11.2) developing via myelodysplastic syndrome after chemotherapy for malignant lymphoma].

A 62-year-old woman was diagnosed as having malignant lymphoma, diffuse large B-cell type. She underwent chemotherapy with the standard dose of CHOP and MINE regimens, resulting in complete remission. Four months later, the myelodysplastic syndrome of RA (refractory anemia) with pancytopenia developed and rapidly progressed to acute myelogenous leukemia (AML-M6) in 4 months. Cytogenetic analysis for the bone marrow specimens of both periods of MDS and AML-M6 revealed complex karyotypic abnormalities involving chromosome 5, 7, 11q23 and 20q11.2. Neither rearrangement of the MLL gene by Southern blot analysis nor tandem duplication of MLL gene by RT-PCR technique was detected. The patient was died from progression of leukemia and pneumonia. The autopsy showed no residual disease of lymphoma-related disease.