Difficulty differentiating between a posterior extradural lumbar tumor versus sequestered disc even with gadolinum-enhanced MRI

Differentiating between posterior extradural tumors versus sequestered lumbar disc herniations may be difficult even utilizing contrast-enhanced MR scans. A 49-year-old male acutely presented with an incomplete cauda equine syndrome. When the MRI showed a L4-L5 posterior extradural lesion that enhanced with gadolinium, an urgent left hemilaminectomy was performed. The lesion proved to be a sequestrated disc herniation rather than a tumor. Notably, postoperatively the patient almost completely recovered after 6-month follow-up. Even on contrast-enhanced MRI studies, posterior extradural sequestered lumbar disc herniations may mimic tumors.