Brachial plexus Schwannoma: a case report involving the middle trunk

• Middle trunk schwannomas of the brachial plexus are extremely uncommon and surgically challenging. • The anterolateral approach enables safe, complete excision with preservation of neural continuity. • Intraoperative neurophysiological monitoring is crucial for functional protection. • Early surgical removal yields excellent neurological and cosmetic outcomes with minimal morbidity. Schwannomas arising from the middle trunk of the brachial plexus represent an exceptionally rare subset of peripheral nerve sheath tumors. While brachial plexus schwannomas account for approximately 5% of all schwannomas, those originating specifically from the trunks constitute only 4–5% of peripheral nerve sheath tumors. The middle trunk, formed exclusively by the C7 nerve root, is particularly uncommon as a site of origin, making detailed documentation of such cases clinically valuable due to the unique surgical challenges and risk of compromising critical motor function. A 28-year-old female presented with a 2-year history of a painless, gradually enlarging 5 cm mass in the left supraclavicular region. Core needle biopsy and MRI confirmed a schwannoma. The patient underwent microsurgical excision via an anterolateral approach with intraoperative neurophysiological monitoring. The tumor was completely excised while preserving the middle trunk integrity. Histopathological examination confirmed schwannoma with characteristic biphasic Antoni A and Antoni B patterns. The patient experienced no postoperative neurological deficits, had uneventful wound healing, and returned to normal activities within three weeks. Complete microsurgical resection of middle trunk schwannomas with preservation of neurological function is achievable through meticulous dissection and intraoperative monitoring. The anterolateral approach provides optimal exposure while protecting surrounding neurovascular structures. Given the rarity of middle trunk involvement and the low recurrence rate following complete excision, early surgical intervention in symptomatic cases is recommended. Continued documentation through detailed case reports remains essential for advancing surgical understanding and optimizing patient outcomes in this challenging anatomical location.