[Trisomy of chromosome 11 in a case of common ALL antigen-positive acute myeloblastic leukemia (FAB-M1)].

In February 1986, a 68-year-old woman was diagnosed as having acute myeloblastic leukemia (FAB-M1). At the time of diagnosis, 86.0% of the bone marrow cells were myeloblastoid, and 15% of these myeloblastoid cells were positive to myeloperoxidase. Surface marker analysis by flow cytometry disclosed granulocyte-associated antigen (MY7) and also lymphocyte-associated antigen (CALLA) on the leukemic cells. Chromosomal banding studies of bone marrow cells revealed trisomy 11 in 6 of 19 metaphases examined and normal karyotype in the others. Complete remission was attained after intensive combination chemotherapy, and has remained for 38 months. Only 19 patients with trisomy 11-associated acute nonlymphocytic leukemia (ANLL) including the present case have been reported. Morphologic analyses have revealed that the frequency of FAB-M1 is high. However, except for the present case, surface marker findings were apparent in only one M5a patient, in whom monocyte-macrophage-associated antigen was detected. Accordingly, careful surface marker studies will be needed to clarify the frequency of acute mixed lineage leukemia in such patients.