Antrochoanal polyps, are solitary polyps arising from the maxillary antrum. They were first described by Killian in 1906. Although their etiology remains unknown, allergy has been implicated.
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.
This photograph of the medial wall of the maxillary sinus shows the widened ostium through which the antrochoanal polyp prolapsed into the nasal cavity. (The photo was taken through a Caldwell-Luc approach)