Philadelphia chromosome-positive acute myelocytic leukemia with French-American-British M2 morphology, refractory to tyrosine kinase inhibitors

Abstract

 We report a 19-year-old male with Philadelphia chromosome (Ph)-positive acute myelocytic leukemia (AML) showing the French-American-British M2 morphology. The karyotype was 46,XY,t(9;22)(q34;q11.2)[17]/46,XY[3] and real-time polymerase chain reaction detected chimeric mRNA consisting of the minor cluster of the BCR gene and the ABL oncogene. The patient failed to respond to treatment with either imatinib or dasatinib, and died of AML progression. Fluorescence in situ hybridization of interphase nuclei revealed that t(9;22)/Ph+ cells comprised a fraction of AML blasts, suggesting that the translocation was a secondary abnormality. It appeared that, in this case, t(9;22)/Ph and expression of the p190 BCR-ABL oncoprotein played a limited role in the development and progression of AML.