Terminal deoxynucleotidyl transferase negative T-cell lymphoblastic lymphoma in aleukemic patient

Precursor lymphoblastic leukemia/lymphoblastic lymphoma (ALL/LBL) is a malignant neoplasm of precursor lymphocytes of T- or B-cell phenotype. We describe the unusual features of an ALL/LBL in an adolescent man in whom the disease presented with involvement of lymph nodes, but without bone marrow and peripheral blood involvement. Immunohistochemical studies revealed that the tumor cells were positive for CD3, CD34 class II, CD10, CD79a and CD99 but negative for TdT. Even though TdT was negative, he received ALL-therapy and is now in remission.