第Ⅲ脑室内脑膜瘤临床病理诊断

Clinicopathological diagnosis of meningioma in 3^(rd) ventriculus

目的分析第Ⅲ脑室内脑膜瘤的临床病理特征,观察其组织类型和来源。方法通过光镜、电镜和免疫组化方法与脑室内其他肿瘤鉴别。结果3例第Ⅲ脑室内脑膜瘤中2例为纤维型,1例为过渡型;3例免疫组化上皮膜抗原(EMA)和波形蛋白(vimentin)均(+)。纤维型脑膜瘤超微结构显示瘤细胞梭形、平行排列,而过渡型脑膜瘤细胞质交织成旋涡等复杂结构,瘤细胞之间可见桥粒。结论第Ⅲ脑室内脑膜瘤罕见。免疫组化和电镜对脑膜瘤的诊断和鉴别诊断有一定帮助。

Objective To study the histological types and origin of meningioma in ventriculus. Methods Light microscopy, electron microscopy and immunohistochemistry were used in differentiating meningioma from other neoplasms in ventriculus. Results Of all three cases, two were classified as fibrous, and the other as transitional; variants showed that all three cases are positive for vimentin and epithelial membrane antigen （EMA）. Distinctive ultrastructural feature of fibrous variants tended to a more parallel alignment, although the transitional variant showed complex interdigitation of tumor cell process. Intercellular junction complexs were frequent and included well-developed desmosomes. Conclusion Meningioma in the third ventricle is very rare and immunohistochemical and ultrastructural features are helpful in differential diagnosis.