These polyps originate in the lining of the maxillary antrum and gradually prolapse through the natural or an accessory ostium into the nasal cavity and enlarge towards the posterior choana and nasopharynx.
They cause nasal obstruction mostly in expiration and serous otitis media if they occlude the eustachian tube. Surgical removal is indicated. Recurrence is frequent and may necessitate a Caldwell-Luc operation.
Endoscopic photograph of right nasal cavity showing an antrochoanal polyp arising from the middle meatus and blocking the right posterior choana.
Coronal CT scan image showing the above antrochoanal polyp arising from the right maxillary antrum and extending into the right nasal cavity through the widened natural ostium of the sinus.
