Terminal Deoxynucleotidyl Transferase Commonly Expresses in Germ Cell Tumors: Evaluation on a Large Series from Multiple Centers

Abstract

Jun Zhou,1,* Suying Wang,2,* Lun Zhu,3 Luting Zhou,1 Hong Zeng,4 Yongli Gan,2 Chaofu Wang1 1Department of Pathology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China; 2Department of Pathology, Ningbo Clinical and Pathological Diagnostic Center, Ningbo, Zhejiang, People’s Republic of China; 3Department of Pathology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People’s Republic of China; 4Department of Pathology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, People’s Republic of China*These authors contributed equally to this workCorrespondence: Chaofu WangDepartment of Pathology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 2st Ruijin Road, Huangpu District, Shanghai, People’s Republic of ChinaEmail [email protected]: The concrete features of expression of terminal deoxynucleotidyl transferase (TdT) are needed to be revealed in male and female germ cell tumors (GCTs).Methods: TdT immunostaining was performed in 195 GCTs, and the tumor and/or tumorous components included seminomas, germ cell neoplasias in situ (GCNISs), dysgerminomas, embryonal carcinomas (ECs), extragonadal germinomas, yolk sac tumors (YSTs), teratomas, and spermatocytic tumors. Twenty-one sex cord-stromal tumors were also added. Expression of the classical germ cell tumor markers (PLAP, OCT4, SALL4, CD117, and D2-40) was compared to that of TDT.Results: Nearly all (tumors or tumorous components) seminomas (99%, 107/108), GCNISs (98%, 51/52), dysgerminomas (94%, 17/18), ECs (100%, 15/15), and extragonadal germinomas (100%, 11/11) were positive for TdT. None of the cells in YSTs (0/38), teratomas (0/19), spermatocytic tumors (0/1), or sex cord-stromal tumors (0/21) were immunoreactive for TdT staining. The normal testicular and ovarian gonadal tissues were also negative for TdT. However, TdT presented with significant loss of antigen immunoreactivity in the paraffin-embedded tissues older than 3 years, giving rise to weak or moderate staining in a subset of cases. The expressions of TdT showed no significances with PLAP, OCT4, SALL4, CD117, and D2-40 during the diagnosis of the most GCTs (P> 0.05), except for with PLAP, SALL4, or CD117 in YST (P= 0.000 each), and D117 (P= 0.000) or D2-40 (P= 0.006) in ECs.Conclusion: Our findings further verify that TdT can serve as a new GCT marker for seminomas, GCNISs, dysgerminomas, ECs, and extragonadal germinomas, with a highly positive rate. Awareness of TdT positivity in GCTs contributes to the prevention of erroneous diagnoses, particularly in the setting of core needle biopsies. To determine the properties where TdT staining may not be apparent in some old archived paraffin-embedded tissues, one could circumvent the potential misinterpretations of false-negative immunohistochemistry results.Keywords: germ cell tumors, immunohistochemistry, TdT, pathological diagnosis

Keywords

• germ cell tumors
• immunohistochemistry
• tdt
• pathological diagnosis