Expression of terminal deoxynucleotidyl transferase (TdT) in classical seminoma: a potential diagnostic pitfall
Seminomas are the most frequent testicular tumors and in spite of specific markers some histological subtypes can be diagnostically challenging due to the potential overlap of morphologic features and a variant antigen expression. Terminal deoxynucleotidyl transferase (TdT) is a DNA polymerase present in hematogones, thymic T cells, lymphoblastic lymphoma/leukemia (LBL), and in some cases of acute myeloid leukemia but so far has not been described to be expressed in seminomas. After observing a reactivity of TdT in one case of seminoma, we analyzed ten additional tumors by immunohistochemistry to determine their spectrum of reactivity for TdT. In all seminoma cases investigated (10/10) as well as in two tumor-associated germ cell neoplasias in situ (2/2) the TdT staining intensity was variable but was often moderate to strong and restricted to the nucleus. We conclude that TdT expression in seminomas could represent a diagnostic pitfall in the differential diagnosis of LBL, particularly because both may lack CD45 and/or CD20 expression and—concerning relapse in long-term survivors of testicular cancer—LBL is the most frequent secondary neoplasm in the patients.
KeywordsSeminona TdT Acute leukemia Testis Aberrant Pitfall
We specially thank Simone Eckhart, Heike Eckhart-Weber and Nicole Neuhaus for their excellent technical support.
Compliance with ethical standards
The authors declare that the study was done according to the ethical standards.
Conflict of interest
The authors declare that they have no conflict of interest.
- 3.Perez-Montiel MD, Plaza JA, Dominguez-Malagon H, Suster S (2006) Differential expression of smooth muscle myosin, smooth muscle actin, h-caldesmon, and calponin in the diagnosis of myofibroblastic and smooth muscle lesions of skin and soft tissue. Am J Dermatopathol 28(2):105–111. https://doi.org/10.1097/01.dad.0000200009.02939.cc CrossRefPubMedGoogle Scholar
- 12.Bahrami A, Ro JY, Ayala AG (2007) An overview of testicular germ cell tumors. Arch Pathol Lab Med 131(8):1267–1280. https://doi.org/10.1043/1543-2165(2007)131[1267:AOOTGC]2.0.CO;2Google Scholar
- 21.Berney DM, Looijenga LHJ, Idrees M, Oosterhuis JW, Rajpert-de Meyts E, Ulbright TM, Skakkebaek NE (2016) Germ cell neoplasia in situ (GCNIS): evolution of the current nomenclature for testicular pre-invasive germ cell malignancy. Histopathology 69(1):7–10. https://doi.org/10.1111/his.12958 CrossRefPubMedGoogle Scholar
- 22.Costi R, Crucitti GC, Pescatori L et al (2013) New nucleotide-competitive non-nucleoside inhibitors of terminal deoxynucleotidyl transferase: discovery, characterization, and crystal structure in complex with the target. J Med Chem 56(18):7431–7441. https://doi.org/10.1021/jm4010187 CrossRefPubMedGoogle Scholar