Pilocytic Astrocytoma Occuring in a Patient Treated with Gamma Knife Surgery: Case Report

We report a case of pilocytic astrocytoma and atypical meningioma occurred within the field of gamma knife surgery for the management of preexisting meningioma. A 76-year old woman received gamma knife surgery for the management of meningioma in the right parietal convexity 9 years ago. Three weeks before admission, left hemiparesis and speech disturbance were developed and magnetic resonance image showed cystic mass with nodular enhancement in the right parietal area. Craniotomy and total removal of mass was performed and the histological diagnosis of atypical meningioma and pilocytic asrtocytoma were done.