[Limited but potential efficacy by graft-versus-leukemia (GVL) for Pro T-ALL].

We present a 22-year-old male diagnosed with pro T-acute lymphoblastic leukemia (ALL). His laboratory test showed 181,900/microL of WBC complicated with lymphoadenopathy, pleural effusion, pericardial effusion and hepatosplenomegaly at the onset. Flow cytometry analysis of the leukemic cells showed cCD3+, CD7+, CD2+, CD1a-, CD3-, CD5-, CD4-, CD8-, CD34+, and HLA-DR+ as a pro T-cell phenotype. The patient was treated with induction therapy followed by 3 courses of consolidation therapy and achieved his first complete remission. He underwent up-front stem cell transplantation (SCT) from an HLA-full matched sibling, with early relapse just before transplantation. The conditioning regimen consisted of fludarabine (100 mg/m2) and melphalan (180 mg/m2). He relapsed with an extramedullary mass (gingival, testis, and femoral muscles) 1 year after transplantation. Since bone marrow involvement was not apparent, he received involved field radiation therapy (25.2 Gy/14 frequencies) in each mass. Six months after extramedullary relapse, bone marrow relapse occurred, and the patient died of sepsis due to Pseudomonas aeruginosa during re-induction therapies. Based on the immature T cell phenotype frequently with myeloid markers, a graft-versus- leukemic effect might be expected after allogeneic SCT for Pro T-ALL and a positive indication of SCT for this disease should be considered.