Variant translocation t(7;922) during lymphoid blastic crisis in a case of Ph1-positive chronic myelogenous leukemia with previous EBV infection.

We report the case of a 19-year-old girl in whom a Ph1-positive chronic myeloid leukemia was diagnosed 10 months after an episode of infectious mononucleosis. Clinical and cytogenetical follow-up demonstrated the appearance of a variant Philadelphia chromosome translocation t(7;9;22) during a blastic crisis characterized by early B-lymphoid elements. The association between the t(7;9;22) variant Philadelphia and the lymphoid blast cells is emphasized, and the importance of Epstein-Barr virus (EBV) infection in the pathogenesis of the disease in this case is discussed.