Retropharyngeal Arteriovenous Malformation

Objective An arteriovenous malformation (AVM) is a vascular anomaly that most commonly occurs in the head and neck as a cutaneous lesion of the cheek, ear, nose, or forehead. This malformation has not been previously reported in the retropharyngeal space. We report the case of a 38-year-old woman with a symptomatic retropharyngeal AVM.

Methods Chart review and review of the literature.

Results The patient presented with 5-month history of solid food dysphagia gradually progressing to include liquids. She denied stridor but recently had trouble exhaling when supine and noted her voice was more “full sounding.” An outside otolaryngologist obtained radiographic imaging that showed a submucosal retropharyngeal mass and subsequently performed a needle biopsy, which revealed an acellular bloody aspirate. On physical examination, the most superior aspect of the retropharyngeal mass was visible with depression of the tongue. Flexible nasopharyngolaryngoscopy displayed the submucosal retropharyngeal mass directly in the midline ∼2 cm in greatest dimension, protruding approximately half a centimeter from the posterior pharyngeal wall and was soft to palpation. Review of contrast-enhanced computed tomographic (CT) scan of the neck demonstrated a 3.6 × 3.0 × 1.5 cm retropharyngeal mass without lymphadenopathy or associated osseous erosion of the anterior cervical spine. Magnetic resonance imaging (MRI) with and without contrast enhancement showed a T1 isointense and T2 hyperintense well circumscribed mass with mild heterogeneous enhancement in the retropharyngeal space. The preoperative differential diagnosis included a benign vascular tumor or malformation, tumor of nonvascular origin such as schwannoma, fibromyxoma, or low-grade sarcoma versus a malignancy. The patient underwent successful transcervical excision of the lesion without pharyngotomy and final pathology noted an AVM. She was seen in follow-up 1 month postoperatively and reported complete resolution of symptoms.

Conclusion In conclusion, we report the unusual presentation, diagnosis, and management of an AVM of the retropharyngeal space. This lesion is extremely uncommon, and may come to the patient’s attention incidentally or due to mass effect on deglutition, pharyngeal sensation, or voice. While complex in this case, imaging is often critical to diagnosis of head and neck AVMs. Diagnostic work-up can include CT, MRI, and angiography. Current treatment of AVMs of the head and neck focuses on angiography and embolization with or without surgery. When surgical resection is possible, it can be curative, as in the case presented here.