Cytogenetic triclonality in T-cell acute lymphoblastic leukemia: A conventional and molecular cytogenetic study

Cytogenetically-unrelated clones are infrequently seen in hematologic malig nancies, and are particularly uncommon in acute lymphoblastic leukemia. We report a case of T-cell acute lymphoblastic leukemia with L2 morphology whi ch demonstrated three cytogenetically distinct clones: 46,XY, t(2;9)(p21;q3 4)/46,XY,del(6)(q21q23)/47,XX,+8. Interphase cytogenetic analysis by fluore scence in situ hybridization (FISH) confirmed the presence of trisomy 8 in a significant proportion of lymphoblasts, while reverse transcription-polym erase chain reaction (RT-PCR) did not show the presence of BCR/ABL fusion. This is the first report describing the occurrence of cytogenetic triclonal ity in de novo T-cell acute lymphoblastic leukemia. (C) Elsevier Science in c., 1999. All rights reserved.