Intravascular Papillary Endothelial Hyperplasia of the Central Nervous System －Four Case Reports

Four rare cases of intracranial intravascular papillary endothelial hyperplasia (IPEH) manifesting as cranial nerve disturbances occurred in 16-, 18-, 24-, and 28-year-old females. Magnetic resonance imaging showed all lesions as isointense with strong enhancement on T1-weighted images, and as hyperintense on T2-weighted images. All lesions were removed via craniotomies. Histological examination found vascular structures and papillary spaces lined with endothelial cells showing immunoreactivity for CD31. Complete removal was curative in two cases, whereas incomplete removal resulted in cure in one case and residual deficits in one case. Iatrogenic deficits should be avoided in IPEH treatment by surgery. Differentiation from neoplasm such as angiosarcoma depends on histological characteristics.