Additional translocation (8;21)(q22;q22) in a patient with Philadelphia-positive chronic myelogenous leukaemia in the blastic phase

We report a case of Philadelphia-positive chronic myelogenous leukaemia in blastic phase with the additional translocation (8:21)(q22;q22), which is f requent in acute myeloid leukaemia but not in chronic myelogenous leukaemia . The t(8;21) was not detected in the chronic phase, and was the only addit ional chromosomal anomaly in the blastic clone. Reverse transcription-polym erase chain reaction revealed the AML1/ETO fusion transcript in the cells o f blastic phase but not in those of chronic phase. Regarding t(9:22). the b reakpoint on chromosome 22 occurred in the CL-BCR region of the BCR gene, r esulting in hybrid BCR/ABL mRNA with an e19a2 junction. Our findings provid ed molecular evidence that t(8;21) can occur as an additional genetic chang e in Philadelphia-positive chronic myelogenous leukaemia.