Cauda equina tumors: a French multicenter retrospective review of 231 adult cases and review of the literature.

Large series of cauda equina tumors in adults are seldom reported. This French series retrospectively reviews 231 cases collected for the congress of the Societe Francaise de Neurochirurgie in 1996. The authors first analyze this series and then discuss the pertinent literature. Schwannoma was the most frequent benign tumor in this series, followed by ependymoma. Very few malignant tumors were recorded; these were usually malignant neurinomas nearly always in neurofibromatosis patients. Some other rare tumors were also recorded, including paragangliomas. This series confirms the importance of the pretherapeutic neurological status in functional prognosis. All schwannomas can be cured, while ependymomas and paragangliomas may recur after a very long delay. Surgery must be as complete as possible, since adjuvant therapies are proven to have little efficacy. This type of tumor requires very long follow-up. Prognosis is good for hemangioblastomas. Sphincter dysfunctions carries a poor prognosis and may appear after primary surgery, more often after treatment of recurrences.