A parapharyngeal space schwannoma arising from the vagus nerve: A case report.

Introduction: Tumours of the parapharyngeal space are rare. Only 0.5% of head and neck tumours occur in this space. Surgical excision of parapharyngeal space lesions is challenging because of the anatomical complexity of the area.
Presentation of Case: A 31-year-old male patient was referred by his general dental practitioner for removal of lower wisdom teeth due to multiple episodes of pericoronitis. At the initial examination, an incidental finding was made of a large fluctuant posterior oropharyngeal swelling. A fluid aspirate was taken from the lesion but this was inconclusive. The patient underwent an urgent MRI and CT neck revealing a large parapharyngeal mass. An incisional biopsy of the lesion confirmed the presence of a vagal nerve schwannoma which was subsequently removed via a transcervical approach.
Discussion: Due to their slow growing and painless nature, they are often not detected until they are large enough to palpate or visualise. It may cause secondary symptoms such as dysphagia, hoarseness and nasal obstruction. This case represents a typical presentation of a parapharyngeal schwannoma and reiterates the subtle and often ambiguous nature of the lesion.
Conclusion: Vagal schwannomas in the parapharyngeal space are rare. They usually present in the form of an isolated intraoral or neck mass. A positive diagnosis is made on imaging and confirmed by histopathological examination. Complete surgical excision is the treatment of choice and recurrence rates are low.
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