Further cytogenetic evidence for a multistep pathogenesis of Ph-positive chronic myelogenous leukemia.

A case of Ph-positive chronic myelogenous leukemia in blastic crisis was studied extensively by means of cytogenetic techniques. Karyotypic features, as well as growth patterns, kinetic data, and rates of sister chromatid exchange, were examined in bone marrow, blood, and pleural effusion cells. The data provide strong evidence for a multistep pathogenesis of the disease, the development of which appears to be linked to mechanisms of clonal selection and genetic imbalance in the malignant cell population.