Filum terminale paraganglioma with associated cyst: a case report

Abstract

Abstract Background and importance: Paragangliomas are neuroendocrine tumors that occur most often within the adrenal glands. The most frequent extra-adrenal locations include the carotid body and the jugular bulb. Filum terminale paragangliomas are extremely rare, with just 33 cases reported to date. Imagistic appearance is similar with other types of intradural extramedullary tumors such as ependymomas and schwannomas. Histopathological examination is the only method of establishing a definitive diagnosis. They are classified as grade I WHO tumors with favorable prognosis in the case of total resection. Clinical presentation: A 46-year-old woman without any relevant medical history was admitted to our Neurosurgical Department, complaining of low back pain with bilateral sciatica. She presented no neurological deficits and routine blood tests, as well as heart rate and blood pressure, were within normal ranges. Lumbar spine MRI with gadolinium enhancement revealed an intradural tumor with irregular, well defined margins and intense homogeneous enhancement, located at the level of the L3 vertebra. It presented an unenhancing intradural cystic lesion that extended cranially up to the level of the L1 vertebra. The tumor and associated cyst were completely resected through L2-L4 laminectomy. The tumor-cyst complex was attached, yet nonadherent to the conus medullaris and nerve roots, which allowed safe total removal. Histopathological examination was suggestive for paraganglioma, a diagnosis confirmed by immunohistochemistry that classified it as moderately differentiated, non-secreting type. Serum metanephrines subsequently determined were within normal ranges. Also, additional imagistic tests consisting of cervical and abdominal ultrasound and contrast enhanced CT scans did not detect any additional tumors. Postoperatively, the patient was neurologically intact, with complete remission of presenting symptoms at 3 months follow-up. Conclusion: Filum terminale paraganglioma is a rare diagnosis which is frequently overlooked. However, gross total resection, a common goal for all spinal tumors, can be curative in these particular cases.