Departments of Pathology.
Department of Pathology, Beijing Fengtai Hospital.
Am J Surg Pathol. 2019 Dec;43(12):1674-1681. doi: 10.1097/PAS.0000000000001342.
Supratentorial extraventricular ependymomas (STEEs) are relatively rare ependymomas, and their pathologic and genetic characteristics are still poorly understood. The aim of this study was to determine the histologic, immunohistochemical, and RELA fusion features, as well as to clarify in more detail the clinical courses of STEEs. Data from a total of 43 patients with STEEs was analyzed retrospectively. The status of RELA fusion was evaluated using fluorescence in situ hybridization. The expression levels of L1CAM, p65, cyclin D1, and p53 were assessed using immunohistochemistry. Progression-free survival and overall survival were calculated via Kaplan-Meier estimation using the log-rank test. Among all 43 STEEs, 65.1% (28/43) are positive for RELA fusion. Interestingly, almost half of the patients with RELA fusion-positive ependymomas are adults (13/28), and 89.3% (25/28) cases are anaplastic ependymomas, which suggests that RELA fusion testing is necessary in adults with STEEs. We investigated the immunohistochemical status of p65, L1CAM and CCND1 protein expression for their ability to predict RELA fusion status. RELA fusion-positive STEEs are frequently associated with expression of p65 (85.2%), L1CAM (85.2%), and CCND1 (81.5%). The accuracy of predicting RELA fusion status was much higher when the expression of p65 and L1CAM was combined, that is, when both were immunopositive. The status of RELA fusion, p53 overexpression, and extent of tumor resection are significantly associated with prognosis.
幕上脑室外室管膜瘤（STEEs）是相对罕见的室管膜瘤，其病理和遗传特征仍知之甚少。本研究旨在确定 STEEs 的组织学、免疫组织化学和 RELA 融合特征，并更详细地阐明其临床病程。回顾性分析了总共 43 例 STEEs 患者的数据。使用荧光原位杂交评估 RELA 融合状态。使用免疫组织化学评估 L1CAM、p65、cyclin D1 和 p53 的表达水平。使用 Kaplan-Meier 估计和对数秩检验计算无进展生存期和总生存期。在所有 43 例 STEEs 中，65.1%（28/43）存在 RELA 融合阳性。有趣的是，几乎一半的 RELA 融合阳性室管膜瘤患者为成年人（13/28），89.3%（25/28）为间变性室管膜瘤，这表明在成人 STEEs 中需要进行 RELA 融合检测。我们研究了 p65、L1CAM 和 CCND1 蛋白表达的免疫组织化学状态，以预测 RELA 融合状态。RELA 融合阳性的 STEEs 常伴有 p65（85.2%）、L1CAM（85.2%）和 CCND1（81.5%）的表达。当同时表达 p65 和 L1CAM 时，预测 RELA 融合状态的准确性要高得多。RELA 融合状态、p53 过表达和肿瘤切除范围与预后显著相关。
