Bilineage T-lymphoblastic/myeloid extramedullary blast crisis in chronic myelogenous leukemia.

The blast crisis of chronic myelogenous leukemia (CML) can be hematological or extramedullary. About 25% of these cases fulfill the criteria for mixed phenotype acute leukemia. We here report a case of a second blast crisis of CML which was extramedullary and was immunophenotypically bilineage T/myeloid.