ependymoma

frequency:
- 6% of intracranial gliomas
- 8-10% of childhood brain tumors
- 63% of spinal intramedullary gliomas
age: supratentorial (any age); posterior fossa (<10 years)
a/w neurofibromatosis
location:
- 4th ventricle (70% of intracranial gliomas)
- lateral ventricle
- 3rd ventricle
- conus
findings:
- sharply marginated isodense / slightly hyperdense mass
- central necrosis (50%); calcification (50%)
- enhancement (80%)
- communicating hydrocephalus (100%) secondary to protein exudate clogging up resorption pathway
- expansion through foramen of Luschka into CPA or caudad into cisterna magna (CHARACTERISTIC)
- dissemination via CSF (10-33%)
DDx of cerebellar ependymoma:
- astrocytoma (hypodense)
- medulloblastoma (hyperdense, 10% calcify)
- trapped 4th ventricle

Yong H. Hahn, MD - 2 February 1995
Last updated: 1 October 2013