Late appearance of a Philadelphia translocation with minor-BCR/ABL transcript in a t(7;11)(p15;p15) acute myeloid leukemia.

We describe a patient with a t(7;11)(p15;p15) acute myeloid leukemia who was subsequently found to harbor the Philadelphia (Ph) translocation, in addition to the t(7;11), at the second relapse. A BCR/ABL transcript was detected at the second relapse by reverse transcription-polymerase chain reaction assay; the leukemic cells had a BCR/ABL fusion gene involving the minor breakpoint cluster region (minor-BCR; situated in intron 1 of the BCR gene). Although the Ph translocation is commonly detected in de novo acute leukemia and chronic myeloid leukemia as the primary leukemia-specific chromosomal translocation, our case suggests that this cytogenetic change might occur as an additional chromosomal change in neoplastic cells. Moreover, minor-BCR/ABL rearrangements may also occur as a late appearance of Ph translocation.