Chromosomes and causation of human cancer and leukemia. XLVII. Severe hypodiploidy and chromosome conglomerations in ALL

A case of acute lymphoblastic leukemia (ALL) of the L1 type with severe hypodiploidy in the marrow cells (modal chromosome number, 36) is described. In addition, most of the metaphases contained chromosome conglomerations which consisted of varying numbers of chromosomes and appeared similar to conglomerations previously observed by us in a case of chronic myelocytic leukemia (CML) in the blastic phase (BP), where some cells contained less than 20 chromosomes. The karyotype of the ALL cells of our case was similar to those of published near-haploid ALL cases, possibly indicative of a common pathway of cytogenetic evolution.