Schwannoma in the upper limbs.

Schwannomas are the commonest tumours of peripheral nerves. Despite the classical description that schwannomas are well encapsulated and can be completely enucleated during excision, a portion of them have fascicular involvement and could not be completely shelled out. A retrospective review for 8 patients was carried out over 10 years. 75% of schwannoma occurred over the distal region of upper limb (at elbow or distal to it). It occurs more in the mixed nerve instead of pure sensory or motor nerve. 50% of patients had mixed nerve involvement. Fascicular involvement was very common in schwannoma (75% of patients). Removal of the tumour with fascicles can cause functional deficit. At present, there is no method (including preoperative MRI) which can predict the occurrence of fascicular involvement; the authors therefore proposed a new system to stratify patients who may benefit from interfascicular nerve grafts. In this group of patients, the authors strongly recommend that the possibility and option of nerve graft should be discussed with patients prior to schwannoma excision, so that nerve grafting could be directly proceeded with patient consent in case there is fascicular involvement of tumour found intraoperatively.