Evidence is adequate that the Philadelphia chromosome (Ph1), first described by Nowell and Hungerford,1 is present in all typical cases of chronic myelocytic leukemia. In contrast to the chronic myelocytic leukemia (CML), few patients have been reported when their disease has been transformed into an acute stage. Furthermore, no Ph1 chromosome was found in some cases.2,3 In the course of our cytogenetic survey of CML, eight patients were studied during the acute stage. This communication reports the cytogenetic findings in these patients.
Materials and Methods
Metaphases were obtained in the following manner: (1) peripheral-blood leukocyte cultures according to the method of Hungerford et al4 with some modifications5; (2) direct bonemarrow preparation using the method of Tjio and Whang6 with some modifications5; and (3) short-term bone marrow incubation. Table 1 summarizes the clinical course and the hematologic data of each patient. The duration