[Neurinoma of the cauda equina (author's transl)]

A rare case of a mobile neuroma of the cauda equina is presented. Myelography, first done by lumbar puncture, showed the tumor at the L1 level. A second myelography, done by suboccipital puncture, showed the tumor at the L3 level, 7 cm more caudal as in the first myelography. Reviewing the literature, 2 similar cases were found. The so-called redundant nerve root is discussed as a possible explanation of the mobility of the tumor. The importance of the precise preoperative tumor localisation is stressed.