颅内脊索样脑膜瘤15例临床病理分析

Chordoid meningioma: a clinicopathologic study of 15 cases

目的 探讨脊索样脑膜瘤临床病理学特征及其鉴别诊断.方法 回顾性分析15例脊索样脑膜瘤的临床和影像学资料、病理组织学形态、免疫组化标记及对患者进行随访,并复习相关文献.结果 15例中男性9例,女性6例,发病年龄12 ～54岁,中位年龄27岁;位于幕上6例,幕下9例.临床表现主要为头痛、头晕,部分患者出现面部麻木、嗜睡、视力下降等症状.影像学检查与典型脑膜瘤相似.MRI显示肿瘤结节状,T1WI等信号、T2WI等或稍高信号,边界较清楚,增强扫描呈明显均匀强化,均未发现骨质破坏.病理大体观察肿瘤呈结节样,直径2 ～8 cm,切面均呈灰白色,实性、质较软.镜下肿瘤细胞排列成小梁状或索状,间质为富含嗜碱性黏液的脊索样区,局部可见典型的上皮型脑膜瘤结构;脑膜上皮细胞胞质嗜酸性,核圆形或卵圆形,染色质细颗粒状,缺乏明显异型性,核分裂象少见.免疫组化：瘤细胞vimentin均（＋）,部分EMA（12/15）、D2-40 （6/13）、S-100 （5/15）和CK（2/15）（＋）;GFAP和brachyury（-）.15例中10例获得随访,均存活,其中1例复发.结论 脊索样脑膜瘤为起源于脑膜上皮的少见低度恶性肿瘤,多见于成年人,确诊需结合临床资料和组织学形态,并辅以免疫组化标记;临床需与脊索瘤和第三脑室脊索样胶质瘤等鉴别.

Purpose To investigate the clinicopathological characteristics and differential diagnosis of 15 cases of chordoid meningioma to enhance cognition of this tumor.Methods Fifteen cases of chordoid meningioma were retrospectively reviewed with analyses of clinical data,radiography,morphology,immunostaining,follow-ups and relevant literature.Results 15 cases of chordoid meningioma consisted of 9 males and 6 females,aging from 12 ～ 54 years,with mean age of 27.Supratentorial tumors were 6 cases,and the other 9 cases were infratentorial tumors.The patients were deficient of unique clinical representation,mainly presenting with headache,dizziness,sometimes facial numbness,somnolence,impaired vision and so on.All of the cases,similar to classical meningioma in the image manifestinations,appeared as nodular,equal signal intensity on T1WI and equal or slightly high signal intensity,with definite boundaries and even enhancement suggested by the enchanced scan,all of which were short of the evidence of bone destruction.In gross observation,nodular-like masses ranged from 2 cm to 8 cm with a gray,solid and soft cutting surface.Histopathologically,tumor cells arranged in trabecula and strand,with the stroma abounded in basophilic chordoid regions and focally typical regions appearing as that of epithelial type meningioma.And the meningeal epithelial cells were characteristic of eosinophilic cytoplasm and round or oval nuclei and fine granular chromatin lacking of prominent atypia and mitotic figures.Immunohistochemically,tumor cells were positive for vimentin,partly positive for EMA （12/15）,D2-40 （6/13）,S-100 （5/15） and CK（2/15）.Follow-up information of 10 cases in 15 cases had been acquired,all of which survived and one relapsed.Conclusion Chordoid meningioma is a rare and low grade tumor derived from meningothelium and usually develops in adults.The correct diagnosis needs clinical data,morphological characteristics in combination with the relevant immunohistochemical markers and the exclusion of chordoma and the third ventricle chordoid glioma.