[Two cases of paragangliomas of the cauda equina--case reports and review of the literature].

Paragangliomas are tumors arising in the paraganglia and rarely occurring in the cauda equina. We report two cases of paraganglioma arising in this region. The tumors exhibited a typical "Zellballen" pattern, and immunohistochemical studies were positive for neuron-specific enolase, but negative for S-100 protein and glial fibrillary acidic protein. Electron microscopic studies confirmed electron-dense neurosecretory types of granules in the tumor cells. Only 23 cases of paragangliomas in this region have been previously reported. A brief review of the literature is included.