TdT Negative Lymphoblastic Lymphoma: A Case Report

Acute lymphoblastic leukemia/lymphomas are tumors made of the precursor b or t cells. precursor b cell type presents as acute leukemia, and most cases of pediatric leukemia are of this type. malignancies originated from t cells are less common and are often manifested as lymphoma in adolescents. terminal deoxynucleotidyl tranferase (tdt) is a dna polymerase that is present in immature pre-b and pre-t cells. tdt enzyme is a sign of cell immaturity and is used to differentiate the dominant types of lymphoblastic lymphoma from mature lymphoma/leukemia cells. tdt is expressed in 90%–95% of lymphoblastic lymphoma cells. childhood tdt negative lymphoblastic leukemia/lymphoma is very infrequent and its prognostic significance remains challenging. it is suggested that tdt negative lymphoblastic leukemia/lymphoma shows poor response to chemotherapy and has a more disastrous course. here, we report a case of tdt negative t-cell lymphoblastic lymphoma in a 10-year-old boy who presented with respiratory distress.