Paraganglioma of the cauda equina. Report of three cases.

The authors report the clinical, radiological, and pathological findings in three cases of paraganglioma of the cauda equina. In one case, magnetic resonance imaging and neurochemical study results are described. No specific identifying features were encountered either clinically or radiologically that were helpful in making a distinction between this and other more common tumors at this site such as ependymoma or neurofibroma. At surgery, these neoplasms were well-circumscribed red fleshy tumors. Histological examination of one paraganglioma showed a superficial resemblance to ependymoma, and this may be particularly true on initial assessment by frozen section or smear. The use of electron microscopy and immunohistochemical demonstration of synaptophysin in these tumors allowed a confident diagnosis to be made. Neurochemical assessment in one case showed very high levels of serotonin and a turnover of dopamine similar to that of human cerebral cortex. Paraganglioma of the cauda equina is an uncommon tumor with just over 50 cases reported in the world literature. The clinical course of these tumors is benign and they should be completely removed at surgery to prevent later recurrence.