Cerebellar ependymoma with overlapping features of clear-cell and tanycytic variants mimicking hemangioblastoma: a case report and literature review.
Cerebellar ependymoma with overlapping features of clear-cell and tanycytic variants mimicking hemangioblastoma: a case report and literature review.
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具有类似血管母细胞瘤的透明细胞和多细胞变体重叠特征的小脑室管膜瘤：病例报告和文献综述
DOI：
10.1186/s13000-017-0619-2
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发表时间：
2017-03-20
影响因子：
2.6
通讯作者：
Wang EH
中科院分区：
文献类型：
--
作者：
Zhang XP;Liu Y;Zhang D;Zheng Q;Wang C;Wang L;Li QC;Qiu XS;Wang EH
背景：透明细胞室管膜瘤和以小脑为基础的血管母细胞瘤的影像学和组织学相似；区分它们是一项诊断挑战。病例表现：一名62岁的中国女性，因间歇性头痛持续8年。计算机断层扫描和磁共振成像显示小脑有肿块。神经影像学提示成血管细胞瘤（HB）。组织学上，肿瘤包括细胞区和少细胞区，细胞呈巢状排列或弥漫性分布；一个高度血管性的区域，肿瘤细胞聚集在一起，并被毛细血管隔开。在低倍镜下，肿瘤模拟了细胞性HB，但在高倍镜下，肿瘤细胞显示出清晰的细胞质，而不是在HB中典型观察到的液泡状细胞质。此外，在巢结构中观察到细长的，类似于伸长细胞的双极元件。虽然这些特征提示室管膜瘤的可能性，但既没有观察到真正的室管膜玫瑰花结，也没有观察到室管膜排列的轮廓。肿瘤以明显的血管性为特征，但未见肾小球形成。部分肿瘤巨细胞灶可见多形性，但未见病理性有丝分裂和栅栏性坏死。大多数肿瘤细胞胶质原纤维酸性蛋白和S100阳性。上皮膜抗原呈副核点状或环状表达。Ki-67指数约为2%。综合患者症状、神经影像学及病理表现，诊断为小脑室管膜瘤（WHO II级）。结论在此，我们报告一例具有透明细胞和细细胞重叠特征的室管膜瘤，并复习文献以评估其真实发病率。当遇到类似的表现时，病理学家应该考虑这种罕见的诊断。
BackgroundImaging and histology of clear-cell ependymoma and cerebellum-based hemangioblastoma are similar; distinguishing between them is a diagnostic challenge.Case presentationA 62-year-old Chinese woman presented with an intermittent headache of 8 years’ duration. Computed tomography and magnetic resonance imaging revealed a mass in the cerebellum. Neurological imaging suggested hemangioblastoma (HB). Histologically, the tumor included cellular and paucicellular areas, in which cells were arranged in nests or diffusely distributed; and a highly vascular area, in which tumor cells were arranged in clusters and separated by capillaries. At low magnification, the tumor mimicked cellular HB, but at high magnification, tumor cells showed clear cytoplasm instead of the vacuolated cytoplasm typically observed in HB. Moreover, spindly, bipolar elements resembling tanycytes were observed within the nest structures. Although these features indicated the possibility of ependymoma, neither true ependymal rosettes nor an ependymal-lined profile was observed. The tumor was characterized by prominent vascularity, but glomeruloid formation was absent. We saw pleomorphism in foci of some tumor giant cells, but pathologic mitosis and palisaded necrosis were absent. Most tumor cells were positive for glial fibrillary acidic protein and S100. Epithelial membrane antigen was expressed with a paranuclear dot-like or a ring-like pattern. The Ki-67 index was approximately 2%. Considering the patient’s symptom, neurological imaging, and pathological findings, she was diagnosed as cerebellar ependymoma (WHO grade II).ConclusionsHere, we report a case of ependymoma with overlapping clear-cell and tanycytic features, and review the literature to evaluate its real incidence. Pathologists should consider this rare diagnosis when confronted with a similar presentation.