Posterior epidural migration of lumbar disc fragment: Case reports and literature review

INTRODUCTION: Posterior epidural migration of lumbar disc fragment (PEMLDF) is a very rare condition that may lead to a serious neurological deficit such as cauda equina syndrome. Magnetic resonance imaging (MRI) findings can often result in cases of PEMLDF being misdiagnosed as extradural masses of other origin or epidural hematomas. In this study, we reported four additional cases of PEMLDF and reviewed the relevant literature. PATIENT CONCERNS: We present four patients with PEMLDF. The mean age of the patients was 53.5 years. Two patients suffered from cauda equine syndrome, and the other two patients complained of radiculopathy. DIAGNOSIS: The MRI findings in each case showed masses with slightly high signal intensity in T2-weighted images, as well as heterogenous and peripheral rim enhancement after contrast enhancement. In some patients there was a tract-like enhancement extending from the outer aspect of the disc to the posterolateral epidural space. A definitive diagnosis was made intraoperatively. INTERVENTIONS: We performed laminectomy and discectomy in all patients. OUTCOMES: The PEMLDF patients with radiculopathy had no complaints of weakness or pain after surgery. Both patients with cauda equine syndrome showed a total recovery post-surgery. CONCLUSIONS: Early diagnosis and treatment via laminectomy and discectomy is critical to achieving the best postoperative outcomes. Understanding the patient's history, recognizing the similar signal intensity of the mass and intervertebral disc on MRI scans, and looking for peripheral rim enhancement, are the keys to the correct diagnosis of PEMLDF.