Schwannoma in the extremity: clinical features and microscopic intra-capsular enucleation

Objective: Schwannomas are the most common type of neoplasm of the peripheral nerves. Enucleation is a standard surgical procedure; however, it occasionally results in iatrogenic nerve injury, even with atraumatic procedures. Herein, we present the clinical characteristics of schwannoma arising in the extremities and discuss the clinical outcomes of extra- and intra-capsular enucleation. Patients and Methods: We reviewed 122 schwannomas treated at our institute. Schwannomas arising from the minor nerve (n=30) or intramuscularly (n=15) were operated using the extra-capsular technique. Of the 77 major nerve schwannomas, 62 schwannomas were treated using the intra-capsular technique and 15 schwannomas using the extra-capsular technique. Results: Neurological deficits following enucleation were significantly lower using the intra-capsular technique than with the extra-capsular technique. The patient age, duration of symptoms, maximum tumor diameter, and site of occurrence were not associated with subsequent neurological deficits. With both techniques, no tumor recurrence was observed at the final follow-up. Conclusion: These results support the use of intra-capsular micro-enucleation as a safe and reliable treatment for every type of schwannoma. To minimize the risk of nerve injury, en bloc resection should not be used because the main purpose of schwannoma surgery is the relief of symptoms, not tumor resection.