SSX 蛋白 C 末端区域的表达是精原细胞瘤的一个有用的诊断生物标志物。

Expression of the C-terminal region of the SSX protein is a useful diagnostic biomarker for spermatocytic tumour.

机构信息

Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.

Department of Anatomical Pathology, Douglass Hanly Moir Pathology, Macquarie Park, New South Wales, Australia.

出版信息

Histopathology. 2021 Nov;79(5):700-707. doi: 10.1111/his.14398. Epub 2021 Aug 6.

DOI:10.1111/his.14398

PMID:33963590

Abstract

AIMS

Spermatocytic tumour (ST) is a rare testicular germ cell neoplasm with few confirmatory biomarkers that can be challenging to diagnose. Like normal spermatogonia, STs are known to express SSX proteins. Recently, a novel SSX antibody directed against a conserved C-terminal region of SSX1, SSX2 and SSX4 (SSX_CT) has emerged as a reliable biomarker for these SSX proteins and synovial sarcoma. However, SSX_CT immunostaining has not been demonstrated in ST. The aim of this study was to assess the diagnostic utility of SSX_CT immunohistochemistry in ST and other tumours in the differential diagnosis with ST.

METHODS AND RESULTS

SSX_CT, OCT3/4 and c-KIT immunohistochemistry was performed on 15 STs, 38 seminomas, 13 embryonal carcinomas, 12 yolk sac tumours, six choriocarcinomas, four teratomas, seven Sertoli cell tumours, and six lymphomas. Staining was scored as negative, rare, focal, or diffuse. SSX_CT was positive in all (15/15) STs, and diffusely positive in 14 of 15 (93%). SSX_CT was positive in 22 of 38 (58%) seminomas; however, only two cases showed diffuse expression. SSX_CT was negative in all other tumours. OCT3/4 was negative in all STs, but positive in all seminomas and embryonal carcinomas. c-KIT was frequently positive in both STs (12/15; 80%) and seminomas (33/38; 87%). OCT3/4 and c-KIT were negative in all other tumours.

CONCLUSIONS

SSX_CT is a valuable and highly sensitive biomarker that supports the diagnosis of ST. Diffuse expression of SSX-CT in STs is also highly specific for ST. Nevertheless, SSX_CT is best used in combination with OCT3/4 when ST is in the differential diagnosis.

摘要

目的

精原细胞瘤（ST）是一种罕见的睾丸生殖细胞肿瘤，其明确的生物标志物较少，诊断具有一定挑战性。与正常精原细胞一样，ST 已知表达 SSX 蛋白。最近，一种针对 SSX1、SSX2 和 SSX4 的保守 C 末端区域的新型 SSX 抗体（SSX_CT）已成为这些 SSX 蛋白和滑膜肉瘤的可靠生物标志物。然而，ST 中尚未显示 SSX_CT 免疫染色。本研究旨在评估 SSX_CT 免疫组化在 ST 及其他与 ST 鉴别诊断的肿瘤中的诊断效用。

方法和结果

对 15 例 ST、38 例精原细胞瘤、13 例胚胎癌、12 例卵黄囊瘤、6 例绒毛膜癌、4 例畸胎瘤、7 例支持细胞瘤和 6 例淋巴瘤进行了 SSX_CT、OCT3/4 和 c-KIT 免疫组化染色。染色结果评分阴性、罕见、局灶性或弥漫性。所有 ST（15/15）均为 SSX_CT 阳性，14 例（93%）弥漫阳性。22 例（58%）精原细胞瘤 SSX_CT 阳性，但仅有 2 例弥漫表达。所有其他肿瘤均为 SSX_CT 阴性。所有 ST 均为 OCT3/4 阴性，但所有精原细胞瘤和胚胎癌均为 OCT3/4 阳性。c-KIT 在 ST（12/15；80%）和精原细胞瘤（33/38；87%）中均为高频阳性。所有其他肿瘤均为 OCT3/4 和 c-KIT 阴性。