Exophytic glioblastoma arising from the cerebellum: case report and critical review of the literature.

Exophytic glioblastoma arising from the cerebellar tonsil is an extremely rare variant within the possible anatomical presentations of the glioblastoma multiforme (GBM). We report the case of a 55-year-old woman who presented with a tumor located at the cranio-cervical junction with compression of the medulla oblongata and consecutive hydrocephalus. Due to the radiological presentation, the first tentative diagnosis was a meningioma. The tumor was microsurgically removed. Histopathological examination of the tumor revealed a GBM WHO IV. The patient underwent a postoperative percutaneous radiotherapy and concomitant chemotherapy with temozolomide. GBM should be also considered in the differential diagnosis of cerebellar tumors.