Endoreduplication in Acute Leukemia

Chromosome studies were carried out on two occasions during the evolution of a case of acute myeloblastic leukemia. A normal karyotype was detected before treatment was started. A second analysis made while the patient was under treatment with 6-mercaptopurine showed a modal number of 44 chromosomes plus a small fragment. Apart from the abnormal karyotype, the leukemic cells showed a high incidence of endoreduplication and a cell with the feature of repeated endoreduplication was observed. The possible significance of these findings in acute leukemia is discussed.