Ependymomas of the conus medullaris and the filum terminale are usually of the myxopapillary subtype. WHO grade I. Usually solitary. Histology: papillary, with microcystic vacuoles, mucosub- stance; connective tissue. No anaplasia, but CSF dissemination occurs rarely (can seed intracranially following removal of spinal tumor). Denovo intracranial lesions also occur rarely. Rare reports of systemic mets. Outside the CNS, may occur in sacrococcygeal subcutaneous tissues from heterotopic rests of ependymal cells.
Surgical removal of filum tumors consists of coagulating and dividing the filum terminale just above and below the lesion.
Myxopapillary ependymomas arise most frequently in adults; approximately 20% occur in children, in whom there is a 2:1 male-to-female bias and a greater tendency for dissemination through cerebrospinal fluid (CSF) pathways.
Myxopapillary ependymoma is the commonest tumor at the filum terminale.
Histological variant of Ependymal tumours
The most characteristic histological feature of myxopapillary tumors is the abundance of intercellular and perivascular mucin and the arborizing vasculature, which tends to form papillae.
It is considered a benign tumour since it is usually encapsulated and anatomically isolated from direct access to lymphatic or other routes of dissemination 1).
The key pathological characteristics of MPE are mucinous degeneration within the vascular connective tissue cores of papillary tumours 2).
The role of radiotherapy after surgery is unclear.