Abnormal chromosome 16 in clonogenic eosinophils from a case of acute myeloid leukemia (FAB,M2).

A case of acute myeloid leukemia (AML, FAB M2) is described in which the leukemic karyotype showed several numerical and structural cytogenetic abnormalities including an abnormal chromosome 16 with breakpoint at band q22, monosomy for chromosomes 5 and 7, and a single pair of double minute chromosomes. There was no patient history of treatment for a previous malignancy or occupational exposure to mutagens. Bone marrow eosinophilia was seen at presentation for refractory anemia with excess blasts in transformation and when AML was diagnosed. When bone marrow buffy coat cells were cultured in soft agar in the presence of colony stimulating factor, 19% of the colonies and 20% of the clusters were of eosinophils. Cytogenetic examination of pooled eosinophil colonies showed the marker chromosomes that identified the leukemic population.