Solitary Extremity Schwannoma: A 20-Year Review of Outcomes

Background: Reports on benign peripheral nerve sheath tumour extirpation over the last number of decades describe varying patient outcomes. We present our outcomes following excision of solitary extremity schwannoma over a 20-year period. Methods: A regional histopathology review was conducted for, "benign nerve sheath tumour" and schwannoma between 2000 and 2020. This search provided 131 histologically confirmed schwannomas that were excised from the extremities of 123 patients. Individual charts were reviewed retrospectively to establish presenting features and post-operative outcomes. Results: One hundred and twenty three patients underwent schwannoma excision, including 8 patients with synchronous tumours. The mean age at presentation was 49 years (range 11-92 years). The most common presenting symptoms were the following: palpable mass (88%), pain (70%), paraesthesia (21%), numbness (13%), and motor deficit (4%). Post-operative follow-up ranged from 1 to 168 months (mean 12.3 months) (N = 99). Fifty-eight cases reported complete resolution of symptoms by end of outpatient follow-up (59%). The remaining reported either residual or new numbness (21%), paraesthesia (11%), pain (10%), weakness (4%), hypertrophic or keloid scar (3%), or a combination. Thirty patients (30%) developed new symptoms post-operatively including numbness (13%), paraesthesia (10%), pain (2%), and weakness (2%). There was a trend towards higher risk of post-operative pain, numbness or paraesthesia in patients undergoing excision of schwannomas on larger mixed nerves than in patients undergoing excision on smaller sensory nerves (P = .0531). Conclusion: Surgical excision of benign schwannomas is a successful procedure, especially for pain management, however, complete symptom resolution cannot be guaranteed, and the risk of new or persisting numbness, paraesthesia, pain, and weakness should be highlighted to patients during the consent process.