Additional t(11;17)(q23;q21) in a patient with Philadelphia-positive mixedlineage antigen-expressing leukemia

We describe very uncommon phenotypic and cytogenetic findings in a 40-year- old female with blast phase of Philadelphia chromosome (Ph)-positive CML. I n addition to the t(9:22)(q34:q11) that was detected in all metaphases, a t (11;17)(q23:q21) was identified in 15 of 20 metaphases. Reverse transcripti on-polymerase chain reaction showed the major and minor bcr/abl fusion tran scripts in the cells from a bone marrow (BM) sample. Fluorescence in situ h ybridization (FISH) analysis also showed that fusion signals of the bo and nhl probes were found in 95% of blastic cells and in 64% of neutrophils. ML L gene rearrangement was also detected in some blastic cells but not in neu trophils by FISH analysis. Phenotypically, blastic cells expressed mixed li neage antigens such as CD34, CD33, CD13. CD19, CD7, and CD41. Immunogenotyp ically. some population of BM cells showed monoclonal rearrangements of imm unoglobulin heavy chain and T-cell receptor gamma chain genes by Southern b lot analysis. Clinical course was aggressive, and therapy was poorly tolera ted. Such findings seem to support an association between Ph and an abnorma lity of 11q23 with poor prognosis, and suggest that the expression of both abnormal genes may be related to this mixed lineage antigen-expressing leuk emia. (C) 2001 Elsevier Science Inc. All rights reserved.