Late-developing Philadelphia chromosomes in a case of T-cell acute lymphoblastic leukemia
Coad, J.E.; Arthur, D.C.; Gajl-Peczalska, K.J.; Litz, C.E.
Leukemia 8(5): 889-894
1994
ISSN/ISBN: 0887-6924 PMID: 8182946 Document Number: 423859
A child with T-cell acute lymphoblastic leukemia (ALL) is presented who at relapse acquired two Philadelphia chromosomes (Ph). Molecular studies at relapse revealed a rearrangement of the major breakpoint cluster region (M-bcr) on chromosome 22. No rearrangements of the immunoglobulin heavy chain or T-cell beta receptor gene loci were demonstrated. This case supports the hypothesis that leukemogenesis in Ph-positive malignancies is a multi-step process, the first step of which may not necessarily involve acquisition of the Ph.