Neuroendocrine Tumor of the Cauda Equina: A Report of a Rare Case With Histopathological and Immunohistochemical Correlation.

Neuroendocrine tumors (NETs) of the cauda equina are rare, generally benign neoplasms. Previously known as paragangliomas, they were renamed as neuroendocrine tumors in the 2022 World Health Organization (WHO) classification of neuroendocrine neoplasms. These tumors typically occur in adults; however, cases have been reported in nearly all age groups. This report describes the case of a 29-year-old male patient with chronic lumbar pain and bilateral radicular neuropathic pain. Magnetic resonance imaging (MRI) findings described an extramedullary intradural lesion at the level of L1-L2. Surgical resection was performed, resulting in rapid symptom resolution. Clinical presentation and imaging findings are often nonspecific; therefore, definitive diagnosis relies on histopathological examination and immunohistochemical analysis. The main differential diagnoses include ependymoma, schwannoma, meningioma, and hemangioblastoma. NET of the cauda equina is a rare entity, with only a few cases reported in the literature; therefore, this case report serves as a guide to establish a diagnosis and its possible surgical management for future patients.