Chronic myeloid leukemia with an e1a3 BCR-ABL fusion protein: transformation to lymphoid blast crisis.

Chronic myelogenous leukemia (CML) results from the neoplastic transformation of a hematopoietic stem cell. CML is cytogenetically characterized by the presence of the Philadelphia chromosome (Ph'). Most patients with CML express e13a2 or e14a2 mRNAs that result from a rearrangement of the major breakpoint cluster regions (M-BCR) generating the 210-kDa (p210BCR-ABL) fusion proteins b2a2 or b3a2 respectively.