1210 - Intradural Extramedullary Schwannoma at the Conus Medullaris

Case Diagnosis: Intradural Extramedullary Schwannoma at the Conus Medullaris

Case Description:
A 40-year-old female presented for severe-acute low back pain with bilateral radicular symptoms, including numbness and tingling with radiating electric shock-like sensations down her legs. She also had difficulty with bowel and bladder movements although she was never completely incontinent. Diagnostic MRI revealed an a T12-L1 intradural extramedullary tumor situated at the level of the conus medullaris. She then underwent T12-L2 laminoplasty for resection of the intradural tumor, which was identified as a WHO grade 1 Schwannoma per pathology. Two weeks following surgery the patient was transferred to inpatient rehabilitation, presenting with bilateral numbness and tingling, as well as decreased strength in her right foot dorsiflexors, hip flexors, and knee extensors. Her symptoms would ultimately improve, and she was ambulating independently with a rollator and right ankle-foot orthosis.

Discussions: Schwannomas arise from Schwann cells of the peripheral nervous system and are not typically found in the brain and spinal cord (central nervous system. Though schwannomas are the most common nerve sheath tumor, they account for approximately 15% of all intradural extramedullary tumors and are associated with neurofibromatosis type 2. Even more uncommon is the location of these schwannomas at the lumbar the level of the conus medullaris. Conus medullaris syndrome is a type of incomplete spinal cord injury of various etiologies, that may present with many symptoms including severe acute low back pain, bilateral numbness, tingling, or weakness, and bladder and bowel dysfunction.

Conclusions:
Although uncommon, intradural extramedullary schwannomas at the conus medullaris should be considered in patient with low back pain and radicular features, especially when conservative management has been inadequate. Early recognition, surgical intervention, and rehabilitation play a crucial role in improving the patient’s recovery and overall function.