Chronic myelogenous leukemia with a Philadelphia chromosome resulting from a complex translocation (2; 9; 22), following an undifferentiated acute leukemia.

This case report concerns a patient with acute leukemia considered at diagnosis to be undifferentiated. Unfortunately, because of the failure of the culture, a cytogenetic evaluation was not possible at that stage. A full remission was induced, but 17 months after the onset of the disease the patient developed chronic myelogenous leukemia. The karyotypes prepared at that time and during the follow-up revealed the presence of a Philadelphia chromosome (Ph1) in all examined cells. This Ph1 resulted from a complex translocation involving chromosomes No. 2, 9, and 22.