目的探讨中枢神经系统非典型畸胎样/横纹肌样瘤(AT/RT)的临床病理特征、免疫组化及鉴别诊断。方法分析6例中枢神经系统AT/RT的临床病理和影像学资料,对肿瘤标本进行常规病理组织学和免疫组化检查,并结合相关文献,探讨其临床病理特征。结果男性4例,女性2例,年龄2~11岁,平均6.7岁。影像学检查显示肿瘤均位于幕上,其中2例位于脑室内。组织学上,肿瘤由横纹肌样细胞及间叶组织或原始神经外胚层成分构成。免疫组化示vimentin、EMA、S-100、NSE和Syn(+),且所有病例均INI1蛋白表达缺失。结论 AT/RT是好发于儿童的罕见的高度恶性胚胎性肿瘤,临床表现为颅内占位性病变的相关症状或体征,病理上肿瘤细胞具有多能分化组织形态和免疫表型;该肿瘤的诊断依赖病理组织学及免疫组化检查,预后较差。 Objective To investigate the clinicopathological, immunohistochemical and differential diagnosis of atypical teratoid / rhabdomyosarcoma (AT / RT) in the central nervous system. Methods The clinicopathological and imaging data of 6 cases of central nervous system AT / RT were analyzed. The histopathological and immunohistochemical examination of the tumor specimens was performed. The clinical and pathological features were also discussed with the related literatures. Results of 4 males and 2 females, aged 2 to 11 years, mean 6.7 years. Imaging studies showed that the tumors were located on the screen, two of which were located in the ventricle. Histologically, the tumor consists of striated muscle-like cells and mesenchymal tissue or primitive neuroectodermal constituents. Immunohistochemistry showed vimentin, EMA, S-100, NSE and Syn (+), and INI1 protein expression was absent in all cases. Conclusions AT / RT is a rare and highly malignant embryonal tumor in children. The clinical manifestations are related symptoms or signs of intracranial space-occupying lesions. The pathological tumor cells have pluripotent differentiation morphology and immunophenotype. The diagnosis depends on histopathology and immunohistochemistry, the prognosis is poor.