ABSTRACT
Pre-T cell acute lymphoblastic leukemia is a relatively rare leukemia. Twenty to 30 % of adult B cell leukemia cases are Philadelphia chromosome positive and it has a therapeutic and prognostic significance. Incidence and outcome of Ph+ T cell acute lymphoblastic leukemia (T cell ALL) is unknown. Only about 25 cases of de novo Ph+ T cell ALL and 44 cases of Ph+ T ALL in blastic phase of CML has been reported. Differentiation between Ph+ Pre-T ALL/LBL and T cell lymphoblastic crises of chronic myeloid leukemia may be difficult. We report a case of adult T cell ALL having Philadelphia chromosome as the cytogenetic abnormality. He was treated with acute lymphoblastic leukemia induction chemotherapy and Imatinib and achieved complete remission.