Summary of Background Data: Since the neurofibromas of L5-S1 level generally extend to the extraforaminal and presacral area, their resection is difficult compared to other lumbar levels.

METHODS: A 46-year-old female presented with severe pain in her left leg. There was a mild motor power loss in her left ankle and toe at plantar and dorsiflexion, and a mild hypoesthesia in the posterior of the left foot and its base. Lumbar computed tomography and magnetic resonance imaging showed a mass in the left intervertebral foramen extending to the extraforaminal presacral area at the level of L5-S1. The tumor was removed through a surgical bone window in the base of the sacrum and resection of L5 transverse process on the left side.

RESULT: The tumor was removed totally. Following surgery, the patient's pain had totally disappeared and there was no alteration in her neurological status.

CONCLUSION: L5-S1 neurofibroma was totally resected through a surgical window in the base of the sacrum. Keywords : Neurofibroma, Sacrum, Surgical approach