A Rare Case of Sequestered Intervertebral Disc Mimicking a Tumour

Abstract

Although intervertebral disc herniation is commonly seen in clinical practice, spinal canal migration of disc fragments is rarely found and can cause a diagnosis dilemma. Intervertebral disc herniation is defined as displacement of disc material beyond its anatomical space. The lumbar spine is the most commonly affected; mostly L4/L5 and L5/S1 region. Disc sequestration refers to the migration of herniated disc fragments into the epidural space, or in rare cases intradural space. Hereby we present a case of sequestered intradural disc at the level of L3/L4 level mimicking a spinal tumour. A 46-year-old man presented with complaints of dull-aching bilateral lower limb pain for the past five years. Then, for the past three months, he experienced numbness over bilateral feet. For the past one month, there is weakness of bilateral lower limbs and he was unable to stand and walk. There is no erectile dysfunction, urinary and faecal incontinence. There was no history of trauma. Examination revealed sensory and motor deficits over bilateral lower limbs from level L3 onwards. There is no spine tenderness. Bilateral straight leg test were negative. MRI spine reported as L3/L4 intradural spinal lesion that demonstrates T1W iso-intensity, predominantly low signal intensity on T2W with minimal area of hyperintensity within. Lesion measured 1.3 x 1.4 x 2.5cm. Laminectomy was done and intra-operatively it was noted sequestered disc material protruding into dura from L2/L3 up to L4/L5. Post-operative period was uneventful and patient regained full muscle power by post-operative day-3. MRI is the gold standard diagnostic tool for spinal pathologies, nevertheless migrated disc fragments can be mistaken for spinal tumour. Hence, it important to keep intervertebral disc prolapse as a differential. In view of the excellent prognosis in these cases, it is not advisable to delay surgery with additional invasive investigation