Li Yingxue, Zhang Xuedong, Wang Aichun, Ding Shanshan, Li Ying, Wang Hongqun, Lv Yali, Shi Huaiyin
Department of Pathology, Chinese PLA General Hospital Beijing 100853, China.
Department of Pathology, Liaocheng People's Hospital Liaocheng 252000, Shandong, China.
Int J Clin Exp Pathol. 2019 Jan 1;12(1):251-258. eCollection 2019.
Synovial sarcoma (SS) is a mesenchymal tumor of uncertain histogenesis which is defined by the translocation t(X;18). Transducer-like enhancer of split 1 (TLE1) as a new immunomarker for SS has offered an alternative to pathologists in distinguishing synovial sarcoma from other mesenchymal neoplasms, especially in limited molecular facilities. The main aim was to study the expression and diagnostic specificity and sensitivity of TLE1 in SS. We performed this immunohistochemical study on 155 SS (107 monophasic, 35 biphasic, and 10 poorly differentiated), 10 fibrosarcomas, 10 angiosarcomas, 10 epithelioid sarcomas, 10 Ewing sarcoma/PNETs and 8 malignant peripheral nerve sheath tumors (MPNST) using TLE1 immunomarker. Furthermore, in problematic cases (n=43), molecular confirmation was performed by fluorescent in situ hybridization (FISH) to detect the t(X;18) translocation. We correlated the TLE1 overexpression with the t(X;18) and other established biomarkers (CD117, CD56, cytokeratin AE1/AE3, EMA, CD99, BCL2, VIM, CD34, S100, Ki67, SMA). TLE1 expression was observed in 76.19% (112/147) of the SS, including 75.96% (79/104) of monophasic, 78.79% (26/33) of biphasic, and 70% (7/10) of poorly differentiated type. 65.99% (97/147) of SS cases showed a strong to moderate staining of TLE1. Other mesenchymal tumors showed very low or absent staining of TLE1 ( < 0.001). The overall sensitivity and specificity of TLE1 expression for the diagnosis of SS were 86.21% and 78.57%, respectively. Further molecular analysis showed that t(X;18) was clearly correlated with TLE1 expression (=0.000). TLE1 is a specific and sensitive diagnostic immunomarker for SS and can be helpful to distinguish SS from other mesenchymal neoplasms.
滑膜肉瘤（SS）是一种组织发生尚不明确的间叶性肿瘤，其特征为t（X；18）易位。作为滑膜肉瘤的一种新型免疫标志物，分裂样增强子转导蛋白1（TLE1）为病理学家在鉴别滑膜肉瘤与其他间叶性肿瘤时提供了一种替代方法，尤其是在分子检测设施有限的情况下。主要目的是研究TLE1在滑膜肉瘤中的表达情况以及诊断特异性和敏感性。我们使用TLE1免疫标志物对155例滑膜肉瘤（107例单相型、35例双相型和10例低分化型）、10例纤维肉瘤、10例血管肉瘤、10例上皮样肉瘤、10例尤因肉瘤/原始神经外胚层肿瘤（PNET）和8例恶性外周神经鞘瘤（MPNST）进行了免疫组织化学研究。此外，对于有疑问的病例（n = 43），通过荧光原位杂交（FISH）进行分子确认以检测t（X；18）易位。我们将TLE1的过表达与t（X；18）及其他已确立的生物标志物（CD117、CD56、细胞角蛋白AE1/AE3、EMA、CD99、BCL2、波形蛋白、CD34、S100、Ki67、平滑肌肌动蛋白）进行了相关性分析。在76.19%（112/147）的滑膜肉瘤中观察到TLE1表达，其中单相型为75.96%（79/104），双相型为78.79%（26/33），低分化型为70%（7/10）。65.99%（97/147）的滑膜肉瘤病例显示TLE1呈强至中度染色。其他间叶性肿瘤TLE1染色极低或无染色（<0.001）。TLE1表达对滑膜肉瘤诊断的总体敏感性和特异性分别为86.21%和78.57%。进一步的分子分析表明，t（X；18）与TLE1表达明显相关（=0.000）。TLE1是滑膜肉瘤一种特异且敏感的诊断免疫标志物，有助于将滑膜肉瘤与其他间叶性肿瘤区分开来。
