Large Schwannoma of the median nerve at the distal forearm: Case report

Introduction: Schwannoma, also known as neurilemmoma is a rare tumor, but it is one of the most common tumors of the peripheral nerves. It originates from Schwann cells of the peripheral nerve sheaths. Schwannoma mostly occurs in adults at the age of 20 to 70. The most common regions are head and neck, but it can occur almost anywhere in the body, or in its organs. Schwannomas are usually up to 2.5cm in size but they may grow up to 4-5. In this paper, the rare case of large Schwannoma of the median nerve in the distal part of the forearm is presented. Case report: A 46-year-old male patient was referred to a plastic surgeon with a diagnosis of lipoma on the anterior side of the distal third of the left forearm. Ultrasound and magnetic resonance imaging were performed and the surgery was done after that. An encapsulated tumor of the median nerve was found, and the tumor was completely removed, without nerve damage. Histological analysis showed a benign Schwannoma of cellular type and biphasic shape. In the postoperative course, there was transient paresthesia. One year after surgery, no tumor recurrence nor neurological deficit were recorded. Conclusion: Schwannoma is the most common benign tumor of peripheral nerves. Schwannomas over 5 cm in size are extremely rare. Appropriate physical examination, preoperative imaging studies, and histological verification are required for the final diagnosis. The method of choice in the treatment of large Schwannomas is complete surgical excision.