Philadelphia chromosome-positive chronic myelocytic leukemia with a supplementary t(4;9)(q21;p22) and long survival.

A Ph-positive chronic myelocytic leukemia (CML) patient was clinically and cytogenetically evaluated during a 12-year period. She acquired a supplementary chromosome abnormality, t(4;9)(q21;p22), at least 5 years prior to transformation to blastic phase. Her blast crisis was accompanied by characteristic chromosome changes, such as trisomy 1, trisomy 17, and multiple Ph chromosomes.