[Double minute chromosomes (DMs) in a case of acute myelomonocytic leukemia]

A 71-year old male was admitted to our hospital because of general malaise and fever. Peripheral blood showed Hb 8.1 g/dl, platelet 7.0 X 10(4)/microliters, and WBC 18.100/microliters with 64% leukemic cells. Bone marrow showed normocellularity with 73.4% leukemic cells. They were positive for peroxidase and alpha-naphthyl butyrate esterase stainings. Serum and urine lysozyme levels were elevated. He was diagnosed as having acute myelomonocytic leukemia (M 4 in FAB classification). Chromosome analysis of bone marrow cells showed 45, XY, -17, t (9; 17) (q22; p13) and double minute chromosomes (DMs) were observed in the 50 cells analyzed. A complete remission (CR) was obtained by DCMP regimen, but he relapsed as acute monocytic leukemia (M 5 b in FAB classification) and died 5 months after diagnosis. DMs appear to be rare in acute leukemia and the clinical and etiologic implications of DMs are discussed.