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

© 2002, C.E. Kahn, Jr.
2002-04-18