Absence of terminal deoxynucleotidyl transferase expression identifies a subset of high-risk adult T-lymphoblastic leukemia/lymphoma

Mod Pathol. 2013 Oct;26(10):1338-45. doi: 10.1038/modpathol.2013.78. Epub 2013 May 24.


Terminal deoxynucleotidyl transferase (TdT) can be downregulated in minimal residual disease of T-acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) after chemotherapy. TdT-negative T-ALL/LBL cases are rare and have not been well characterized. We studied the clinicopathologic features of de novo T-ALL/LBL patients treated at our institution during 2003-2011, with an emphasis on immunophenotype and survival of TdT-negative versus TdT-positive cases. Absence of TdT expression was defined as <10% lymphoblasts positive. Seven (12%) TdT-negative cases were identified from a cohort of 59 de novo T-ALL/LBL. The TdT-negative and TdT-positive cases were similar with regard to gender, percentage of patients with a high leukocyte count (>100 × 10(9)/l), central nervous system involvement, and an abnormal karyotype. However, patients with TdT-negative T-ALL/LBL had a significantly higher rate of disease progression and shorter overall survival. Although not statistically significant, TdT-negative T-ALL/LBL cases were associated with an older median age and higher percentage of 'early T precursor' (ETP) immunophenotype than TdT-positive cases. Absence of TdT expression identifies a subset of high-risk T-ALL/LBL that overlaps with, but is not identical to, the ETP leukemia, providing additional prognostic value.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Child, Preschool
  • DNA Nucleotidylexotransferase / metabolism*
  • Female
  • Humans
  • Immunophenotyping
  • Leukemia-Lymphoma, Adult T-Cell / metabolism*
  • Leukemia-Lymphoma, Adult T-Cell / pathology
  • Male
  • Middle Aged
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / metabolism*
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / pathology
  • Prognosis
  • Survival Rate


  • DNA Nucleotidylexotransferase