Secondary acute promyelocytic leukemia with t(8;21) and t(9;22) at onset and loss of the philadelphia chromosome at relapse

The translocation (8;21) is a typical marker of the M2 subtype of acute nonlymphocytic leukemia, whereas the Philadelphia (Ph) chromosome is predominantly associated with chronic myelogenous leukemia, and seldom with immature acute leukemia, either lymphoblastic or nonlymphoblastic. Furthermore, the association between t(8;21) and a Ph in the same cell is extremely rare. We present a case of secondary acute promyelocytic leukemia with a karyotype 46,XY,t(8;21), t(9;22) at onset. At relapse the patient lost the Ph, while maintaining the t(8;21). This apparently paradoxical pattern of cytogenetic features and evolution is discussed.