Unusual cause of non-discogenic sciatica: Foraminal lumbar root schwannoma

Schwannomas are tumors of peripheral nerves that develop from the nerve sheath. Foraminal schwannomas are rare and account for 1-5% of all spinal schwannomas. The lumbosacral root schwannoma is a rare cause of sciatica and may raise confusion in diagnosis with late discovery of the tumor.

We report the case of a patient 30 years of age with chronic left sciatica in whom lumbosacral magnetic resonance imaging (MRI) revealed a tumor involving the S1 nerve root. The excision of the tumor was simple. Histological examination revealed a benign schwannoma. The evolution was favorable postoperative with no neurological deficit, which confirms the good prognosis of this tumor.

Nerve root schwannomas should be considered in the differential diagnosis of sciatica, especially when signs and symptoms of sciatica cannot be simply explained by prolapsed disc syndrome, which can often delay the diagnosis. Through this case presentation, the authors try to discuss the clinical and radiological features of this condition.