Under electron microscopy, MBF can be seen in capillary endothelial cell in the papillary center of GPP and microvilli in the top of cell;

• 电镜下见脉络丛乳头状瘤的乳头中心毛细血管内皮细胞可见膜桥连性开窗，细胞顶部见微绒毛;