Precursor T-lymphoblastic lymphoma is a type of non-Hodgkin lymphoma in which too many T-cell lymphoblasts (immature white blood cells) are found in the lymph nodes and spleen. Also called T-lymphoblastic lymphoma, it is most common in young men. Precursor T-lymphoblastic lymphoma is a type of non-Hodgkin lymphoma in which too many T-cell lymphoblasts (immature white blood cells) are found in the lymph nodes and spleen. Also called T-lymphoblastic lymphoma, it is most common in young men. Of all cancers involving the same class of blood cell, 2% of cases are precursor T lymphoblastic. This article incorporates public domain material from the U.S. National Cancer Institute document 'Dictionary of Cancer Terms'.