@Article{Pęksa2022,
journal="Polish Journal of Pathology",
issn="1233-9687",
volume="73",
number="2",
year="2022",
title="Diagnostically misleading aberrant terminal deoxynucleotidyl transferase expression in germ cell tumors",
abstract="Terminal deoxynucleotidyl transferase (TdT) is a unique type of DNA polymerase predominantly expressed in precursor lymphoid cells and acute lymphoblastic leukemia. It participates in the junctional diversity of T-cell receptors and immunoglobulins. Recently, aberrant TdT expression was found in seminomas. Here, we evaluated the expression of TdT in our cohort of germ cell tumors (GCTs) with two anti-TdT antibody clones.  We included 173 cases of testicular GCTs, 5 ovarian dysgerminomas, and one gonadoblastoma in the study. Tissue microarrays containing representative tumor samples were constructed and subsequently stained with anti-TdT monoclonal rabbit antibody EP266 (Dako) and TdT rabbit polyclonal antibody (Cell Marque).   Expression was assessed with the H-score. No specific nuclear reaction was observed for the polyclonal anti-TdT antibody. The H-score values varied between the histological subtypes for the EP266 antibody. Positive nuclear staining was consistently seen in germ cell neoplasia  in situ , seminoma, dysgerminoma, and embryonal carcinoma. Pure tumors had higher TdT H-scores than the mixed ones. Teratomas, yolk sac tumors, and choriocarcinomas were almost uniformly negative.   Our study confirms that aberrant expression of TdT by testicular and ovarian GCTs exemplifies a potential diagnostic pitfall in histopathological diagnostics.",
author="Pęksa, Rafał
and Kunc, Michał
and Bieńkowski, Michał
and Popęda, Marta
and Biernat, Wojciech",
pages="159--165",
doi="10.5114/pjp.2022.120098",
url="http://dx.doi.org/10.5114/pjp.2022.120098"
}