Chronic myelocytic leukemia with eosinophilia, t(9;12)(q34;p13), and ETV6-ABL gene rearrangement: case report and review of the literature.

Chronic myelocytic leukemia (CML) is a chronic myeloproliferative disorder characterized by cytogenetic or molecular evidence of Philadelphia (Ph) chromosome, t(9;22)(q34;q11). Mild to moderate eosinophilia is commonly seen in CML. However, eosinophilia as a dominant feature of CML is extremely rare. We describe a case of Ph(-) CML with eosinophilia. Loeffler endocarditis, and t(9;12)(q34;p13) that resulted in an ETV6-ABL gene rearrangement/fusion identified to the best of our knowledge, for the first time by using commercially available fluorescence in situ hybridization probes.