Abstract：
Ependymomas (EPN) are central nervous system neoplasms that exhibit an ependymal phenotype. In particular, supratentorial EPN (ST-EPN) must be differentiated from more aggressive entities such as glioblastoma, IDH-wildtype. This task is frequently addressed with the use of immunohistochemistry coupled with clinical presentation and morphological features. Here we describe the case of a young adult presenting with migraine-like symptoms and a temporoinsular-based expansile mass that was first diagnosed as a GBM, mostly based on strong and diffuse oligodendrocyte transcription factor 2 (OLIG2) expression. Molecular characterization revealed a ZFTA::RELA fusion, supporting the diagnosis of ST-EPN, ZFTA fusion-positive. OLIG2 expression is rarely reported in tumors other than GBM and oligodendrocyte-lineage committed neoplasms. The patient was treated with radiotherapy and temozolomide after surgery and was alive and well at follow-up. This report illustrates the need to assess immunostains within a broader clinical, morphological and molecular context to avoid premature exclusion of important differential diagnoses.
摘要：
室管膜瘤（EPN）是表现出室管膜表型的中枢神经系统肿瘤。特别是,必须将幕上EPN（ST-EPN）与更具侵袭性的实体（如胶质母细胞瘤）区分开来，IDH-野生型。该任务经常通过使用免疫组织化学以及临床表现和形态学特征来解决。在这里，我们描述了一个年轻的成年人出现偏头痛样症状和以颞岛为基础的膨胀性肿块的情况，该肿块最初被诊断为GBM。主要基于强和弥漫性少突胶质细胞转录因子2（OLIG2）的表达。分子表征揭示了ZFTA::RELA融合，支持ST-EPN的诊断，ZFTA融合阳性。在GBM和少突胶质细胞谱系定向肿瘤以外的肿瘤中很少报道OLIG2表达。该患者在手术后接受了放疗和替莫唑胺治疗，并且在随访中存活良好。本报告说明了在更广泛的临床范围内评估免疫染色的必要性，形态学和分子背景，以避免过早排除重要的鉴别诊断。
