Posterior Fossa Ependymoma

**Semantic type:** Neoplastic Process

**Definition:** A circumscribed ependymoma that arises in the posterior fossa. The diagnosis of posterior fossa ependymoma should be made either when molecular analysis for DNA methylation profiling cannot assign a molecular group (not elsewhere classified -NEC) or when the molecular analysis for DNA methylation profiling was unsuccessful or not reported (not otherwise specified-NOS).