T-lymphoid or T/myeloid blast phase of chronic myeloid leukemia in the era of tyrosine kinase inhibitor therapy: a report of 14 cases

Philadelphia chromosome-positive T-cell acute lymphoblastic leukemia: a case report

Philadelphia chromosome-positive (Ph+) T-cell acute lymphoblastic leukemia (T-ALL) is a rare and aggressive type of acute leukemia. The Philadelphia chromosome is the hallmark of chronic myeloid leukemia (CML). The differentiation between Ph+ T-ALL and T-cell lymphoblastic crisis of CML may be problematic in some cases. Here, we report a rare case of de novo Ph+ T-ALL that presented a diagnostic challenge. The overall clinical, immunophenotypic, cytogenetic, and xenotransplantation results suggest a diagnosis of Ph+ T-ALL. The patient was treated with induction chemotherapy including imatinib followed by haploidentical stem cell transplantation and achieved complete remission.

Evidence for BCR/ABL1-positive T-cell acute lymphoblastic leukemia arising in an early lymphoid progenitor cell

BCR-ABL1-positive leukemias have historically been classified as either chronic myelogenous leukemia or Ph+ acute lymphoblastic leukemia. Recent analyses suggest there may be a wider range of subtypes. We report a patient with BCR-ABL1 fusion positive T-cell ALL with a previously undescribed cell distribution of the fusion gene. The examination of sorted cells by fluorescence in situ hybridization showed the BCR-ABL1 fusion in the malignant T cells and a subpopulation of the nonmalignant B cells, but not nonmalignant T cells or myeloid or CD34+ progenitor cells providing evidence that the fusion may have occurred in an early lymphoid progenitor.