Cauda equina tumors in adults.

Large series of cauda equina tumors in adults are seldom reported. This stu dy was based on the 231 cases collected in the French neurosurgery units fo r the congress of the Societe Francaise de Neurochirurgie in October 1996. Schwannomas were the most frequent benign tumor in this series, followed by ependymomas. Very few malignant tumors were recorded, usually malignant ne urinomas nearly always arising in patients with neurofibromatosis. Some oth er rare tumors were also observed including paragangliomas. This series confirms the contribution of pre-therapeutic neurological statu s to functional prognosis. All schwannomas can be cured while ependymomas a nd paragangliomas may recur after a very long delay. Surgery must be as com plete as possible since adjuvant therapies have proven to have little effic acy. This type of tumor requires a very long follow-up. Prognosis is good f or hemangioblastoma. When present, abnormal sphincter function is an argume nt for poor prognosis. It may appear after primary surgery or more often af ter treatment of recurrence.