Philadelphia Chromosome-Positive T-Cell Acute Lymphoblastic Leukemia with p190 BCR-ABL1 Fusion: A Case Report and Literature Review

ABSTRACT Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) is a well-documented entity in B-cell lineage ALL; however, its presence in T-acute lymphoblastic leukemia (T-ALL) remains exceedingly rare. The BCR-ABL1 fusion gene, resulting from the t(9;22)(q34;q11) translocation, primarily manifests as the p190 isoform in ALL, but its role in T-ALL is not well understood. We present a rare case of Ph+ T-ALL with p190 BCR-ABL1 expression, highlighting the diagnostic challenges, therapeutic approach, and clinical outcome. In addition, we review the current literature on this unusual leukemic subset.