Chronic myelogenous leukemia with a hypooctoploid cell population

A patient with chronic myelogenous leukemia who underwent transformation from the accelerated phase to the chronic phase with interferon-α treatment is reported. On admission, the numbers of myeloblasts and promyelocytes in the peripheral blood and bone marrow were 7.0% and 12.8%, respectively. The platelet count was 633.6 × 104/μl, and megakaryocytes were frequent in the bone marrow. In the accelerated phase, cytogenetic analyses revealed a hypotetraploid and a hypooctoploid cell population with two and four Philadelphia chromosomes, respectively, in the bone marrow specimen. The hypooctoploid clone disappeared with administration of interferon-α and the hypotetraploid clone also subsequently disappeared.