Ependymoma of the filum terminale: treatment and prognostic factors in a series of 28 cases.

A series of 28 ependymomas arising in the filum terminale was divided into two groups based on the presence/absence of connections with the conus medullaris and/or roots of the cauda equina. Group A comprised ependymomas having no connections with the contiguous structures and group B those either infiltrating or adhering to such structures. Factors having a positive influence on the prognosis (risk of recurrence) were: 1) clinical history under one year (p < 0.01); 2) confinement of tumour to the filum terminale (p < 0.01); 3) total tumour removal (p < 0.05). Postoperative radiotherapy had no appreciable effect on outcome. The combination of significant factors was in turn significantly influenced by the mode of tumour growth, which proved to be the cardinal factor in prognosis. This point is examined in the light of the published work.