Ependymoma

Epidemiology
~200 cases per year in US
Most common in children < 5 years
Occasionally diagnosed in adults
No known risk factors

Pathology
Grade I - myxopapillary ependymoma; most commonly seen in filum terminale of spinal cord
Grade II - Ependymoma
Grade III - Anaplastic ependymoma

Clinical
Classic location is posterior fossa; 2/3 originate around the fourth ventricle
Risk of CSF seeding 5 to 10%

Staging
MRI of brain and spine should be done preoperatively to avoid post-surgical artefact that may mimic drop mets in the spine or elsewhere in the CNS
Postop MRI should be obtained within 48 hours
If no LP done before resection, wait 2 weeks after surgery to decrease the chance of postoperative false positive CSF findings

Prognostic factors
Extent of resection
Age (younger is worse)
Grade

Treatment
Maximal resection is essential
Myxopapillary tumors can be followed closely after complete resection
Other histologies, subtotal resections are usually given adjuvant RT
Since most lesions are located in the posterior fossa, cerebral cortex can usually be spared
Typical dose 59.4Gy (patients older than 18 mos); 54Gy (younger than 18 mos)
Target is tumor bed + 1cm
CSI not indicated; grade III patients may get adjuvant chemotherapy

Further reading:
St. Jude experience, PMID 19274783
Neurocognitive outcomes, PMID 15284268