CYTOGENETIC STUDIES ON ACUTE NONLYMPHOCYTIC LEUKEMIAS FOLLOWING POLYCYTHEMIA-VERA

Chromosome studies were performed on 15 patients suffering from acute nonlymphocytic leukemia (ANLL) and in 1 patient in a preleukemic state following polycythemia vera (PV). Clonal chromosome abnormalities that were present in all cases were clearly nonrandom and involved chromosomes 1, 5, 7, 8, 9, 11 and 21. A subdivision of ANLL into 2 categories occuring in the course of PV is proposed from the clinical, hematologic and cytogenetic data: one resembling de novo ANLL with rapid initial evolution, easy classification into 1 group of the FAB [French-American-British] nomenclature and simple chromosome abnormalities; the other resembling induced leukemia, often with more progressive initial evolution, difficulty or impossibility of classification into 1 group of the FAB nomenclature and complex chromosome abnormalities. Consequences for the commitment level of progenitor cell from which the leukemia clones originate are discussed.