Risk factors for neurological deficits and recurrence in sporadic and syndrome-associated spinal nerve sheath tumors.

Abstract

Spinal nerve sheath tumors (SNSTs) are most commonly benign tumors that present with pain. The aim of the study was to assess factors associated with new neurological deficits and recurrence in surgically treated SNSTs. All surgically treated SNSTs at a single institution over a 10-year period (2014-2023) were identified by searching the institution's histopathological database and neuro-oncology multidisciplinary team conference. Patient demographics, presenting symptoms, tumor characteristics, surgical procedures, use of intraoperative monitoring, neurofibromatosis (NF) status, neurological outcomes, and complications were recorded. There were 169 tumors in 165 patients (52.7% female, mean age 48.6 years) included in this analysis. The median duration of symptoms was 8.5 months (range 0.5-120 months). Presenting symptoms were pain (71.6%), motor deficit (26.6%), sensory deficit (22.5%), and bladder incontinence (5.9%), with incidental findings in 7.7% of cases. The median tumor diameter was 2.5 cm (range 0.6-21 cm). The gross-total resection rate was 63.9% and subtotal resection (STR) rate was 36.1%. Intraoperative neurophysiological monitoring (IONM) was used in 21.9% of cases. NF (NF type 1, NF type 2, or schwannomatosis) was present in 18.9%. Schwannoma was the most common diagnosis (82.8%, 140/169), followed by neurofibroma (13.6%, 23/169) and malignant peripheral nerve sheath tumor (MPNST) (3.6%, 6/169). Four of 6 cases (66.6%) of MPNST were concurrent with NF. The overall complication rate was 22.5% (38/169). New motor weaknesses were seen in 5.3% of cases and were associated with larger tumors (p = 0.007). Nerve root sacrifice of motor nerves produced new motor deficit in 14.3% of cases that were intact preoperatively. The rate of new sensory deficit was 3.6% (6/169). Tumor recurrence occurred in 7.1% (12/169) of cases and was associated with female sex, STR, MPNST, and NF. The median time to recurrence was 22 months (range 1-48 months). IONM use was not associated with fewer complications. These findings suggest that surgical treatment of SNST is a safe and effective procedure. There was low risk of new motor weakness, with or without nerve root sacrifice, following surgery. Recurrence rates were low; however, the risk was increased for patients with STR, NF, MPNST, or neurofibroma. MPNST and SNST in NF are complex and difficult to manage, behaving differently than benign and sporadic nerve sheath tumors.