부산대학교 도서관

目的 探讨上皮样胶质母细胞瘤(E-GBM)的临床病理学特征及鉴别诊断要点.方法 收集8例E-GBM临床及影像学资料、观察其病理学形态及免疫表型,检测其分子改变,并复习相关文献,探讨E-GBM的病理诊断和鉴别诊断要点.结果 E-GBM患者8例,其中男性6例,女性2例.7例发生于幕上,好发于颞叶,以头昏、头痛为主要症状.MRI显示边界清楚或不清,病变呈长T1长T2信号,周围见片状水肿带,增强扫描显示不规则强化,瘤周水肿明显,可见囊性变、出血、钙化.镜下观察,肿瘤由上皮样细胞区域、横纹肌样细胞区域及局灶的经典型胶质母细胞瘤(GBM)区域构成,上皮样细胞片状或弥漫生长,局部失去粘附性,部分由围绕血管生长,形成乳头状结构;上皮样细胞呈圆形、卵圆形,细胞膜明显,胞质丰富,嗜酸性,细胞核大小不一,位于胞质一侧,瘤细胞异型性明显,核分裂象易见;血管丰富,可见厚壁血管及微血管明显增生,可见肾小球样血管;坏死呈地图状,1例呈栅栏状坏死;局灶可见钙化.免疫组化:GFAP、Nestin、S-100、INI-1 及 vimentin(+),Nanog、MDM2、p53、c-Met 不同程度(+),1例 EGFR(+);Ki-67增殖指数为10％ ～30％,而 NeuN、NF、Olig-2、IDHl、p16、Myogenin、MyoDl、SMA、desmin、CK、LCA、 HMB45、Melan-A、CD68、Syn、CD30、CD34、PTEN均为(-).分子病理表现:FISH显示8例 lp/19q 均未见缺失;未检测到EGFR扩增;MS-PCR显示2例MGMT启动子发生甲基化,6例MGMT启动子未发生甲基化;HRM-PCR显示8例均未见IDH1突变,4例BRAF V600E突变.结论 E-GBM罕见,需与横纹肌样脑膜瘤、中枢神经系统非典型畸胎样/横纹肌样瘤(AT/RT)、恶性黑色素瘤、转移性伴横纹肌样特征的大细胞肺癌、伴横纹肌样细胞特征的肾细胞等进行鉴别,其确诊需结合组织病理学及免疫组化进行综合分析.
To investigate the clinicopathologic features and the differential diagnosis of intracranial epithelioid glioblastoma (E-GBM). Methods The clinical and radiological data of eight cases of E-GBM were collected, and their pathological, immunohistochemical, and molecular features were examined. Analysis of lp/19q was conducted by FISH, MGMT methylation by MS-PCR, and detection of IDH1R132 and BRAF V600E mutation by HRM-PCR were performed. The pathological diagnosis, differential diagnosis and molecular genetic features of the tumors were discussed based on these cases with review of related literature. Results The eight cases of E-GBM included 6 males and 2 females, with 7 cases being supratentorially located, predominantly in the temporal lobe. Headache was the main symptom. MRI showed well-circumscribed or ill-circumscribed lesions, hyperintense signal on T1-weighted images and T2-weighted images, peripheral edema, irregularly enhanced after gadolinium injection, cystic, hemorrhage, and focal calcification. Microscopy revealed that the tumors were composed of epithelioid cells and some rhabdoid cells, focal classic glioblastoma. The epithelioid and rhabdoid cells showed focal discohesion, distinct cell membrane, eosinophilic cytoplasm, and a laterally positioned nucleus. All tumors showed high mitosis; seven cases exhibited zonal necrosis, and one case exhibited palisading necrosis. All tumors were rich in thin-walled or thick-walled blood vessels and microvascular hyperplasia as well as glomeruloid blood vessels. Immunohistochemical findings showed that epithelioid cells were positive for GFAP, vimentin, nestin, S-100 and INI-1; olig-2 was focally expressed in two cases, and EMA was focally expressed in three cases. The epithelioid cells were negative for NeuN, NF, IDH1, P16, myogenin, MyoDl, SMA, desmin, CK, LCA, CD117, HMB45, melanA, CD68, Syn, CD34, CD30 and PTEN. Immunohistochemistry showed epithelioid cells were positive for Nanog, MDM2, P53, c-Met in eight cases, and only one case was focally EGFR positive. Molecular findings demonstrated that FISH showed no deletions of lp/19q in any case, EGFR FISH revealed no amplification in any case, MS-PCR showed a methylated MGMT promoter in two cases, and an unmethylated MGMT promoter in six cases; HRM-PCR showed no IDH1 mutation in any case. The BRAF V600E mutation was detected in four cases. Conclusion E-GBM is a rare variant of glioblastoma, with histological epithelioid features. Differential diagnosis includes meningioma, central nervous system atypical teratoid/ epithelioid tumor (AT/RT), melanoma, and metastatic tumors with epithelioid features, and the diagnosis requires a combination of histopathological and immunohistochemical findings.