Department of Diagnostic Pathology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-Ku, Tokyo, 104-0045, Japan.
Department of Pathology, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
Brain Tumor Pathol. 2023 Apr;40(2):133-141. doi: 10.1007/s10014-023-00451-y. Epub 2023 Feb 22.
In the World Health Organization tumor classification (fifth edition), central nervous system (CNS) tumors with BCOR internal tandem duplications have been recognized as a new tumor type. Some recent studies have reported CNS tumors with EP300::BCOR fusions, predominantly in children and young adults, expanding the spectrum of BCOR-altered CNS tumors. This study reports a new case of high-grade neuroepithelial tumor (HGNET) with an EP300::BCOR fusion in the occipital lobe of a 32-year-old female. The tumor displayed anaplastic ependymoma-like morphologies characterized by a relatively well-circumscribed solid growth with perivascular pseudorosettes and branching capillaries. Immunohistochemically, OLIG2 was focally positive and BCOR was negative. RNA sequencing revealed an EP300::BCOR fusion. The Deutsches Krebsforschungszentrum DNA methylation classifier (v12.5) classified the tumor as CNS tumor with BCOR/BCORL1 fusion. The t-distributed stochastic neighbor embedding analysis plotted the tumor close to the HGNET with BCOR alteration reference samples. BCOR/BCORL1-altered tumors should be included in the differential diagnosis of supratentorial CNS tumors with ependymoma-like histological features, especially when they lack ZFTA fusion or express OLIG2 even in the absence of BCOR expression. Analysis of published CNS tumors with BCOR/BCORL1 fusions revealed partly overlapping but not identical phenotypes. Further studies of additional cases are required to establish their classification.
在世界卫生组织肿瘤分类（第五版）中，具有 BCOR 内部串联重复的中枢神经系统 (CNS) 肿瘤已被确认为一种新的肿瘤类型。一些最近的研究报告了具有 EP300::BCOR 融合的 CNS 肿瘤，主要发生在儿童和年轻成人中，扩大了 BCOR 改变的 CNS 肿瘤谱。本研究报告了一例新的高级别神经上皮肿瘤 (HGNET)，在一名 32 岁女性的枕叶中存在 EP300::BCOR 融合。肿瘤显示出类似于间变性室管膜瘤的形态学特征，表现为相对界限清楚的实性生长，伴有血管周围假玫瑰花结和分支毛细血管。免疫组织化学染色显示 OLIG2 局灶阳性，BCOR 阴性。RNA 测序显示 EP300::BCOR 融合。德国癌症研究中心 DNA 甲基化分类器 (v12.5) 将肿瘤归类为具有 BCOR/BCORL1 融合的 CNS 肿瘤。t 分布随机邻域嵌入分析将肿瘤与具有 BCOR 改变的参考样本的 HGNET 接近。BCOR/BCORL1 改变的肿瘤应纳入具有类似于室管膜瘤组织学特征的幕上 CNS 肿瘤的鉴别诊断中，特别是当它们缺乏 ZFTA 融合或表达 OLIG2 时，即使在缺乏 BCOR 表达的情况下也是如此。对具有 BCOR/BCORL1 融合的已发表 CNS 肿瘤的分析显示出部分重叠但不相同的表型。需要进一步研究更多的病例来确定它们的分类。
