A 25-year-old woman with a mass in the hippocampus.

Angiocentric gliomas (AG) have only recently been described. We encountered a 25-year-old woman with AG who had a history of epilepsy for two years. MRI revealed that there was a solid tumor in the hippocampus. The tumor was totally removed. Histologically, the spindle tumor cells proliferated around small parenchymal vessels with perivascular pseudorosettes. The tumor cells of the hippocampus surface umbilicated forming rosettes. Immunohistochemistry demonstrated positivity for GFAP, Vimentin and S-100, but were negative for neurofilament protein, Syn, CgA and P53. EMA had "dot-like" positive staining. The proliferation index was less than 1%. The location of the tumor and the pathological findings confirm that the diagnose was AG. Epilepsy disappeared after the operation. When fully resected these tumors have a good prognosis.