Ependymoma: a heterogeneous tumor of uncertain origin and limited therapeutic options.

Ependymomas are tumors that typically occur with an age-based site preference, with adults harboring supratentorial and spinal tumors and pediatric tumors being mainly in the posterior fossa. Despite their similar histologic appearance, the prognosis varies significantly by age and tumor location, with a better prognosis in increasing age. The mainstay of treatment remains surgical excision with or without radiation therapy as the tumor biology is poorly understood and chemotherapy is generally considered to be ineffective. More recently, molecular biology data have increased our understanding of the genetic and epigenetic changes that drive these tumors, but still it will take a lot of effort to find effective chemotherapeutic regimens. Currently, we are trying to define a subset of tumors, for which radiation therapy can be avoided.