Giant cystic Intradural extramedullary tumor of the lumbar spine mimicking arachnoid cyst: A case report.

Introduction: Schwannoma, also known as neurilemmoma, is a benign tumor commonly found around the spinal nerve roots. Large, solitary cases of cystic degeneration within the extramedullary intradural compartment (IDEM) can be challenging for preoperative diagnosis. Furthermore, these cases are not extensively documented in the medical literature.

Case Presentation: We report a case of giant invasive IDEM schwannoma in a 28-year-old man who presented with intermittent pain radiating to the left thigh without numbness. Magnetic resonance imaging (MRI) showed a complex cystic lesion within the spinal canal from the inferior end plate of L4 to the mid-body of S1.

Clinical Discussion: The patient underwent a series of surgical procedures, including laminectomy and decompression at the L4-L5 level for resection of the tumor. Histopathological examination confirmed the diagnosis of schwannoma. The patient had a favorable postoperative recovery and experienced a resolution of symptoms.

Conclusion: The giant cystic lumbar schwannoma, although rare, necessitates careful diagnosis and management. The utilization of contrast-enhanced MRI aids in distinguishing it from other lesions. In cases of cystic spinal schwannoma, the lesion walls tend to be thicker and more irregular compared to other cysts, including arachnoid cysts. Histopathological examination should be utilized to identify these lesions intraoperatively. Surgical excision is the primary treatment, and complete excision should be attempted whenever feasible.