Schwannoma of the Hand: Importance of Differential Diagnosis & Microsurgical Dissection

ABSTRACT

PURPOSE: The schwannoma is a benign peripheral nerve tumor arising from the Schwann cell of the nerve sheath. Only 2-8% of schwannomas arise in the hand and wrist. Misdiagnosis is frequent such as ganglion and neurofibroma. This article documents and clarifies the clinical features of schwannomas arising in the hand and wrist, and emphasizes importance of differential diagnosis and meticulous surgical extirpation under magnification. METHODS: The author reviewed clinical features of 15 patients with pathologic final diagnosis of schwannoma developed in hand and wrist during the last 12 years from 1998 through 2009. The review included the sex, age of onset, duration, preoperative diagnosis, location, involved nerve, preoperative symptoms and. Postoperative sequelae after surgical extirpation of the lesion with magnification, or without magnification of the surgical fields. RESULTS: The chief complaints were slow growing firm mass in all patients, and followed by pain in 40%, and paresthesia in 40% respectively. The lesions were developed solitarily in 14 patients(93%). The postoperative pathologic diagnosis and preoperative diagnosis were coincided with only in 6 patients(40%). Other preoperative diagnosis were soft tissue tumor in 4 patient(26.6%), and ganglion in 3 patients(20%), and neurofibroma in 2 patients(13%). In all patients who were undergone surgical excision under the fields of magnification, all symptoms were subsided without any sequelae. Meanwhile muscle weakness, paresthesia, hypoesthesia and/or accidental nerve resection developed after surgical excision with naked eye. CONCLUSION: Schwannoma in hand most commonly appears as a slow growing solitary mass with pain or paresthesia. The chance of preoperative misdiagnosis was 60% in this series. To provide good prognosis and less sequelae, careful and elaborate diagnostic efforts and meticulous surgical excision under the magnification are necessary in management of schwannoma.