Full-Endoscopic Interlaminar Approach for a Posteriorly Migrated Lumbar Disc Sequestration in a Patient Presenting with Cauda Equina Syndrome and Atypical Magnetic Resonance Imaging Findings: Case Report

Background and Clinical Significance: Posterior epidural migration of a sequestered disc fragment is a very rare entity that may present significant diagnostic challenges, due to radiological characteristics that may mimic other lesions; Case Presentation: A young adult male presented with acute deteriorating low back pain, paraparesis, and urinary incontinence. Magnetic Resonance Imaging (MRI) revealed a massive posterior intraspinal mass causing critical canal stenosis. Although the dorsal location and severe mass effect initially suggested a neoplasm, the complete absence of contrast enhancement strongly pointed toward an avascular lesion. Given the patient’s rapid neurological decline, an emergency full-endoscopic left-sided L4-L5 interlaminar approach was employed, and a massive free disc fragment was removed. The patient achieved complete motor and sphincter recovery within a month, with mild paresthesia resolving by six months; Conclusions: Posterior epidural migration of a sequestered disc fragment is a rare entity that should be included in the differential diagnosis of posterior intraspinal masses with atypical MRI characteristics. The full-endoscopic interlaminar approach is a viable minimally invasive surgical option.