Chromosomes and causation of human cancer and leukemia: XXXIX. Usual and unusual findings in Ph1-positive CML

Open Access
Publisher Website
Google Scholar
Abstract
The chromosomal changes in the leukemic cells of 48 patients with Ph1‐positive CML are reported. The karyotypic findings in the chronic phase (CP) and blastic phase (BP) were similar to those reported in the past, with +8, an extra Ph1, and an iso (17q) being the most common anomalies observed in BP. Unusual cytogenetic findings were observed in one patient whose cells (from lymph nodes, bone marrow, and blood) were characterized by very marked hypodiploidy and hypo‐haploidy, with some of the cells having less than 20 chromosomes. In each of these very hypodiploid metaphases, conglomerations of darkly stained and condensed chromosomes were seen. These conglomerations consisted of a few to eight chromosomes. The role played by these chromosomes in the genesis of severe hypodiploidy is uncertain. The patient was thought to have „lymphoid”︁ types of leukemic cells in BP, with an extramedullary origin of such cells, particularly in lymph nodes, playing a major role in the genesis of BP. The reported cases of near‐haploidy with Ph1‐positive CML and those with constitutional translocations with CML have been tabulated and the possible significance of the cytogenetic abnormalities discussed.