Surgical treatment of rare cauda equina tumours.

Background: Cauda equina tumours (CET) are rare and usually benign. Treatment of schwannomas and benign ependymomas, which are the most frequent histopathological types of CET, is now well established. However, management of other presumed histopathological types of CET is still a matter of debate. The aim of this study was to assess the incidence and the surgical treatment of rare CET.

Method: A retrospective study was carried out on 176 adult patients surgically treated for CET in our two departments from 1994 to 2010. We reviewed pre- and postoperative symptoms, magnetic resonance imaging aspects, surgical findings, outcome including operative neurological morbidity, local recurrence rate and operative mortality, and incidence of rare CET.

Findings: Seventeen percent (30 patients) of CETs operated on were neither schwannomas nor benign ependymomas. Half of these cases were benign tumours, with paragangliomas being the most common. Two patients were in poorer clinical condition after surgery, one patient experienced a local recurrence, and one died following surgery, from the progress of his disease (Von Hippel-Lindau disease). The other half were malignant tumours, with metastases being the most common. One third of the patients were worsened by surgery, and the mortality rate was 1/3 at 8 months (1-27 months).

Conclusions: Roughly one in six CET were neither schwannomas nor benign ependymomas. This study demonstrated the efficiency of surgery for rare benign CET with a low local recurrence rate. Surgical treatment of rare malignant CET led to a high rate of increased postoperative neurological deficit in patients with a reduced life expectancy.