Posterior Epidural Migrated Lumbar Disc Fragment at L2-3 Level Mimicking an Extradural Spinal Tumor: A Case Report

Abstract

Introduction: Disc sequestration is well known as a perforation of the fibrous ring and posterior longitudinal ligament, and migration of the fragment to the epidural space.

Case report: A 62-year-old man complained of increased pain and hypoesthesia and muscle weakness of the left lower limb that had started 1 month before. Magnetic resonance imaging revealed a tumor-like mass at the L2-3 level on the posterior side of the dura. The fragment was strongly adhered to the dural sac and was resected piece by piece. Disc herniation recognized at L2-3 compressed the left L3 nerve root and was removed. The histopathological diagnosis was consistent with a degenerated intervertebral disc. All symptoms improved after the surgery.

Conclusion: There are few reports about the posterior migrated disc herniation at higher lumbar level. It may be associated with fused segments from L4 to the pelvis due to the previous surgery, which impacted the adjacent segment.

Keywords: Posterior epidural disc fragment; disc herniation; fused spine; spinal tumor mimic.

Figure 1

The lesion at L2–3 was hypointense on T1-weighted images (a and d), hyperdense on T2-weighted images (b and e), and showed rim enhancement after administration of gadolinium (c and f).

Figure 2

X-ray and computed tomography showed complete fusion at L5–6 and almost autofusion at L4–5 due to the degenerative disc change of the adjacent segment before fusion surgery (a–c). The L6 vertebra was fused with the sacrum alar through the right transverse process and the sacroiliac joint was fused at both sides (d).

Figure 3

After the excision of the ligamentum flavum, the extruded disc fragment was readily visible posterolateral to the thecal sac (a). A fragment of the lumber disc herniation compressed the thecal sac under sonography (b). The fragment of the lumber disc herniation was resected from the dural sac ©.