Paraganglioma in the cauda equina. A case report.

Paraganglioma of the cauda equina is rare, and diagnosis is difficult. A 47-year-old woman presented with backache, with a 2-year history of pain radiating in her right lower extremity. Initial neurologic examination revealed mild hypaesthesia in the L4 dermatome on both sides. Spine MRI showed a well-delinated intradural extramedullary mass compressing the spinal cord. It extended from L2 to L4, with anterior compression of the spinal cord which was displaced posteriorly. Clinical and radiological findings suggested an ependymoma. Surgical decompression was performed from L2 to L4 through lumbar laminectomy under microscope. Intraoperatively, the patient experienced unexplained paroxysmal hypertension while manipulating the tumour, which was not relieved by hypotensive medication but resolved immediately after resection of the mass. Postoperatively, the neurologic status improved and the radiating pain was relieved. Histopathologic examination showed cellular perivascular arrangement which looked like 'pseudorosettes'. Taken together, these histologic and radiologic findings suggested a benign myxopapillary ependymoma. However, immunohistochemical examination showed reactivity with synaptophysin and chromogranin. Finally, histological examination of the specimen revealed a 'Zellballen' pattern of paraganglioma, and the final diagnosis of paraganglioma with secreting function was confirmed. Paraganglioma is a rare tumour that can exhibit a secreting function causing paroxysmal hypertension which may be life threatening. Therefore, the differential diagnosis is important. The diagnosis is based on close examination of the clinical, radiologic and pathologic findings.