Intradural, extramedullary hemangioblastoma at the level of the conus medullaris: illustrative case

BACKGROUND: Hemangioblastomas are rare, slow-growing, and highly vascularized tumors that typically occur in the cerebellum and spinal cord. The cervical and thoracic regions are the most common spinal sites, and the tumors are usually intramedullary. OBSERVATIONS: The authors report the case of a man whose chest computed tomography performed for managing coronavirus disease 2019 incidentally revealed an enhancing area in the spinal canal at T12–L1. The patient reported low back pain as well as leg numbness and tingling. Magnetic resonance imaging of the lumbar region with and without gadolinium contrast demonstrated an intradural, extramedullary lesion with displacement of the conus medullaris. The differential diagnosis included a schwannoma and myxopapillary ependymoma. Bilateral T12–L1 laminectomies were performed with resection of the mass. The general pathologist rendered the frozen section diagnosis of a spindle cell neoplasm, suggesting the differential diagnosis of schwannoma or myxopapillary ependymoma. Immunohistochemistry was positive for inhibin, GFAP, reticulin, CD31, SOX-10, S100, and EMA. A World Health Organization grade 1 hemangioblastoma was confirmed. LESSONS: Spinal surgeons should be cognizant of the presenting symptoms and differential diagnosis of hemangioblastomas at the level of the conus medullaris, especially when the tumor is diagnosed incidentally. Additional investigations should be performed to determine whether von Hippel-Lindau syndrome is associated with the hemangioblastoma, as this combination portends a different clinical presentation, multiple tumor locations, and tumor recurrence following resection.