Giant Lumbosacral Meningioma Without Dural Attachment in an Adolescent: A Rare Diagnostic and Surgical Challenge

Objective: To present a rare case of a huge, nondural-based atypical lumbosacral meningioma. Background: Meningiomas are dural-based tumors that originate from arachnoid cap cells of the dural sac. Their clinical presentation is mainly due to compression of the neighboring neural structures. Management of meningiomas includes maximal surgical resection with/without radiation therapy. Herein, we present the 24th case of nondural-based, giant, lumbosacral meningioma in a young girl, a presentation that could be considered as the rarest presentation of meningiomas. Case Presentation: The patient was a 13-year-old girl with persistent low back pain and walking difficulty for one month before our visit, without any response to conservative therapy. Imaging studies showed a huge lumbosacral meningioma at the level of L3 to S3 vertebrae. Results: Tumor was completely resected through a posterior spinal approach. The post-operative course lacked any significant morbidity. In her one-year follow-up, complete neurological recovery without cerebrospinal fluid (CSF) leakage and any sign of regrowth of the tumor was documented. The pathologic investigation revealed meningioma grade 1 (WHO 2021 classification). Conclusion: We presented a rare case of lumbosacral, non-dural based meningioma (WHO Grade I), which is atypical in terms of size, location, and severe adhesion to spinal nerve roots and the dura. Keywords: atypical lumbosacral meningioma, surgical resection, non-dural tumors, cerebrospinal fluid, nerve roots