室管膜下瘤(subependymoma)为中枢神经系统生长缓慢的良性肿瘤,位于脑室,丛状胶质细胞包埋于丰富的纤维基质中,常伴微囊形成,组织学分级属WHOⅠ级。可发生于不同性别的所有年龄阶段,以中年和老年男性好发。其组织学特点为簇状细胞核埋入致密的胶质纤维基质中形成分叶状结构(图1),多伴小囊腔形成(图2),核分裂象偶见或缺如,肿瘤细胞胞核形态 Subependymoma is a benign tumor with slow growth in the central nervous system. It is located in the ventricle and the plexiform glial cells are embedded in abundant fibrous matrix, often accompanied with microcapsules. The histological grade is WHO grade Ⅰ. It can occur in all age groups of different genders and is good for middle-aged and older men. Its histological characteristics of the cluster nucleus into dense dense glial fibrillar matrix formation of lobular structure (Figure 1), accompanied by the formation of small cysts (Figure 2), occasional mitotic figures like or tumor cell nuclei form