ACR Codes: 2.3
Antrochoanal polyps (ACPs) are benign polypoid masses derived from inflamed mucosa of the maxillary sinus that pass through the maxillary ostium into the middle meatus. They are almost always unilateral and can extend into the oropharynx. The pathogenesis is still unknown, however it has been suggested that allergies and chronic sinusitis are associated with the development of ACPs.
ACPs most often occur in children and young adults, but they can occur at any age. They make up 4-10% of all nasal polyps but up to 33% of nasal polyps in the pediatric population. A predilection for males has been shown at a rate of about 70% of total cases.
The presentation of ACPs most often consists of nasal obstruction and nasal drainage. Other presenting symptoms include rhinorrhea, epistaxis, snoring, foreign body sensation, halitosis, headache, postnasal drip, anosmia, dyspnea, dysphagia, obstructive sleep apnea, and cachexia.
Diagnosis is made by CT scan and nasal endoscopy. CT scan will show a mass filling a maxillary sinus that grows through the maxillary ostium and into the middle meatus and posterior choana. Nasal endoscopy will reveal a bright white mass in the middle meatus. ACPs may also be observed during examination of the oropharynx as a white mass behind the uvula. Biopsy is done during surgery to confirm the diagnosis, which shows pseudostratified ciliated epithelium and edematous stromal tissue with inflammatory cell infiltration.
ACPs are always treated with surgical resection via functional endoscopic sinus surgery. It is important that the antral part of the polyp is removed to avoid recurrence. This surgery is effective and has a low complication rate. Complications include cheek anesthesia, cheek swelling, injury to the infraorbital nerve, and damaging the growth of teeth and growth centers of the maxilla in children.