Ependymomas are glial tumours which arise from ependymal cells lining the ventricular cavities. Two-thirds arise from the fourth ventricle with the remainder in the third ventricle and in the caudal part of the spinal cord. They occur predominantly in children in which they constitute about 10% of all intracranial tumours. Most present within the first two decades of life. Calcification occurs in 40% of cases.
Lesions of the fourth ventricle present with features of intermittent raised intracranial pressue due to hydrocephalus. Cerebellar signs - ataxia and vertigo - may also occur. Vomiting is a common early sign and indicates brain stem involvement. CT scan shows an isodense mass with or without calcification that resides in the fourth ventricle. It often shows enhancement with contrast.
Treatment is by surgical excision though this may be excluded if there is infiltration into the fourth ventricle whereupon post-operative radiotherapy is indicated.
The median 5 year survival rate is about 40%.
Last reviewed 01/2018