The present study describes the case of a 63-year-old woman presenting with headache, dizziness and vomiting due to a an ovoid mass in the left pre-bulbar cistern, apparently arising from the lower clivus and the foramen magnum. The clinical history revealed the subtotal removal of a right cerebellar low-grade glioma 15 years previously and subsequent conventional 60-Gy radiotherapy. Notably, following gross total resection, histopathological examination showed microscopic features that resulted in a diagnosis of anaplastic ependymoma. The patient underwent surgery to remove the mass and post-operative chemotherapy with temozolomide. A progressive improvement of neurological signs and symptoms was observed during the postoperative course. At the 6-month follow-up, the patient was free from clinical and radiological recurrence. The unusual features of this rare secondary brain tumor were the extrassial location in the posterior fossa, the unusual age-associated location of the histological subtype and the fact that it closely mimicked a skull-base meningioma.
Keywords: post irradiation tumors; radiation-induced ependymoma; radiation-induced meningioma; skull base approach.