Brachial Plexus Schwannoma With Neural Foraminal Extension

Schwannomas are benign nerve sheath tumors arising from the proliferation of active peripheral Schwann cells. Although schwannomas represent the most common benign peripheral nerve sheath tumors, brachial plexus schwannomas are rarely documented in the literature, presenting a unique challenge due to their complex anatomical location and potential for significant complications. In this report, we present a 36-year-old man presenting with progressive swelling over the right side of his neck, gradually enlarging during the past 10 years. On clinical examination, a firm, nonpulsatile, mobile mass measuring 4 × 3 cm with smooth, round borders was observed on the right side of the neck, with no motor or sensory abnormalities in the right upper limb. Magnetic resonance imaging revealed a fusiform mass along the right C6 nerve root extending to the upper trunk, exhibiting homogeneous postcontrast enhancement. Fine needle aspiration cytology indicated a spindle cell mesenchymal neoplasm, consistent with schwannoma. Given the clinical findings, imaging, and the patient's discomfort, surgical intervention was decided. A firm, glistening yellowish tumor extending intraforaminally was dissected free from its capsule, and the intraforaminal segment was meticulously dissected and removed in piecemeal fashion to achieve gross total resection while preserving the integrity of the C6 nerve root. Histological analysis confirmed the diagnosis of schwannoma. During a 12-month follow-up period, the patient developed a hypertrophic scar at the incision site, which was managed with intralesional steroid injections. No sensory or motor deficits were noted, and follow-up magnetic resonance imaging scans at 3, 6, and 12 months showed no evidence of recurrence.