Cervical Sympathetic Chain Schwannoma in the Parapharyngeal Space: A Rare Case and Literature Review.

Introduction: Schwannomas are rare, typically benign tumors arising from Schwann cells. Parapharyngeal space tumors account for only about 0.5% of all head and neck neoplasms, with schwannomas representing ~31% of these. Among these, schwannomas originating from the cervical sympathetic chain (CSC) are particularly rare but clinically important. These tumors grow slowly and often present with vague symptoms such as mild dysphagia, which delays diagnosis. Imaging techniques such as computed tomography (CT) and magnetic resonance imaging aid evaluation. This report presents a rare CSC schwannoma case and reviews 54 others to highlight diagnostic and clinical features.

Case presentation: A 44-year-old Arab female presented with a 4-month history of mild dysphagia and right-sided throat discomfort. Physical examination revealed a smooth, non-tender submucosal bulge along the right lateral pharyngeal wall. Contrast-enhanced CT demonstrated a well-circumscribed, homogeneously enhancing mass in the right paravertebral space, displacing the carotid sheath-radiologically consistent with a schwannoma. The tumor was excised via a transcervical approach and found intraoperatively to originate from the CSC. Histopathology confirmed a benign schwannoma. Postoperatively, the patient developed first-bite syndrome (FBS), managed conservatively with gradual symptom improvement. At 6-month follow-up, she remained asymptomatic with no evidence of recurrence.

Conclusion: Parapharyngeal schwannomas are rare neurogenic tumors that often present with vague symptoms, delaying diagnosis. CSC schwannomas, though uncommon, carry a high risk of postoperative complications such as FBS and Horner's syndrome. Accurate imaging, early recognition, and multidisciplinary planning are essential for safe surgical resection and optimal patient outcomes. This case, alongside our literature review, emphasizes the importance of correlating tumor origin with clinical behavior and postoperative sequelae.