透明细胞型脑膜瘤6例报道并文献复习

Retrospective study of 6 cases with Clear Cell Meningioma

摘要:

目的 探讨透明细胞型脑膜瘤（Clear cell meningioma，CCM）临床、影像及病理学特征。方法 回顾性分析了2005年至2012年2月经手术及病理证实的6例透明细胞型脑膜瘤。结果 MRI表现为T1加权像信号不均匀者5例，呈类球形2例，分叶状型3例，扁平型1例；可见硬膜尾征者5例，黑环征不完整者或缺乏者5例，1例黑环征基本完整；轻度水肿4例，中、重度水肿各1例；瘤内、瘤周囊变各1例；肿瘤钙化2例。行Simpson I级切除4例，Simpson Ⅱ级切除2例，术后1例34月后复发。病理学检查示水样透明细胞呈片状排列，细胞呈多边形，胞质透明，胞核居中，中间交织着透明变性的胶原。免疫组化显示上皮膜抗原EMA（+）、波形蛋白Vimentin（+），神经胶质纤维酸性蛋白GFAP（-）、 S-100蛋白（-）、细胞角蛋白CK（-），同微囊型脑膜瘤、透明细胞型室管膜瘤、少突神经胶质瘤和透明细胞型转移癌等相鉴别。结论 透明细胞型脑膜瘤MRI表现多为信号不均匀，无黑环征或黑环征不完整，明确诊断主要依靠组织病理学检查，免疫组化有助于其鉴别诊断。CCM侵袭性较强，同良性脑膜瘤相比术后更易复发。

Abstract:

Objective To investigate the clinical, MR imaging and pathological features of clear cell meningioma.Methods We retrospectively studied six cases of clear cell meningioma operated in our institute after 2005.Results Five cases display hypointense and heterogeneous intensity on T1-weighted imaging. The shapes of the tumor include rounded (2/6), lobular (3/6) and en plaque (1/6). Dural tail sign is noted in five cases. There are five meningiomas with partial or complete disappearance of the peritumoral band. Peritumoural edema emerge in all cases and include mild (4/6), moderate (1/6), severe (1/6). The are one intratumoral cystic change and one peritumoral cystic change. CT scans show two tumors with calcification. Simpson I excision was attained in four patients, and Simpson Ⅱ excision in two cases. One case recurred after 34 months. Microscopic examination of the tumors reveals sheets of polygonal cells with abundant clear cytoplasm and distinct cellular outlines. The sheets of tumor cells are separated by hyalinized vascular stroma and bands of collagen. Immunohistochemistry shows that the epithelial membrane antigen and vimentin are positive, while glial fibrillary acidic protein, S-100 and cytokeratin are negative.Conclusions They commonly display heterogeneous intensity on T1-weighted imaging. Most of them exhibit partial or complete disappearance of the peritumoral band. Histopathologic examination can confirm the diagnosis. Clear cell meningioma is more aggressive and higher recurrence rate for benign Meningiomas.