Biclonal acute monoblastic leukemia showing del(7q) and trisomies 9 and 22

Cytogenetic biclonality is a rare phenomenon in acute myeloid leukemia. We report a case of acute monoblastic leukemia with biclonal cytogenetic abnormalities, showing an abnormal clone with an unusual occurrence of trisomy 9 and trisomy 22, in addition to a second clone with deletion of the long arm of chromosome 7 as the only abnormality. The significance of these findings in leukemogenesis is discussed.