目的探讨第三脑室脊索样胶质瘤临床病理学特征及其鉴别诊断,提高对脊索样胶质瘤的认识。方法对3例脊索样胶质瘤进行光镜、免疫组化标记及电镜观察,并复习3例患者的临床资料及相关文献。结果3例患者中2例为女性,1例男性,发病年龄32~46岁,主要症状为记忆力下降、头痛、呕吐、昏睡、短期失去知觉等,女性常有月经不调。肿瘤均位于第三脑室附近,直径3~4cm。光镜下瘤细胞呈团簇状或条索状分布于空泡状黏液样基质中。瘤细胞圆形到多边形,胞质红染,未见核分裂,无坏死及血管内皮增殖。肿瘤周边间质内散在淋巴细胞、浆细胞浸润。免疫表型示所有瘤细胞表达GFAP和vimen-tin,少数瘤细胞表达S-100及EMA,2例中有灶性瘤细胞表达CKpan及CD34。结论第三脑室脊索样胶质瘤是一种独特的、罕见的中枢神经系统肿瘤,诊断主要依靠临床特点、组织病理特征、免疫表型及电镜检查。 Objective To investigate the clinicopathological features and differential diagnosis of the third ventricle chordoid glioma and to improve the understanding of the chordoma. Methods Three cases of chordoid glioma were observed by light microscopy, immunohistochemistry and electron microscopy. The clinical data and related literatures of three cases were reviewed. Results Of the 3 patients, 2 were female and 1 was male. The age of onset was 32-46 years. The main symptoms were memory loss, headache, vomiting, drowsiness and short-term unconsciousness. Women often had irregular menstruation. Tumors are located in the third ventricle near the diameter of 3 ~ 4cm. Under the light microscope, the tumor cells were clustered or clumped in vacuolar myxoid-like matrix. Tumor cells rounded to polygons, cytoplasmic red staining, no nuclear fission, no necrosis and vascular endothelial proliferation. Tumor interstitial interstitial scattered lymphocytes, plasma cell infiltration. Immunophenotype showed that all tumor cells expressed GFAP and vimen-tin, few tumor cells expressed S-100 and EMA, and 2 cases had focal tumor cells expressing CKpan and CD34. Conclusions The third ventricle chordoid glioma is a unique and rare central nervous system tumor. The diagnosis mainly depends on clinical features, histopathological features, immunophenotype and electron microscopy.