Differences Between Antrochoanal Polypi and Ethmoidal Polypi

Features	Antrochoanal Polypi	Ethmoidal Polypi
Age	Common in children	Common in adults
Aetiology	Infection	Allergy or multifactorial
Number	Solitary	Multiple
Laterality	Unilateral	Bilateral
Origin	Maxillary sinus near the ostium	Ethmoidal sinuses, uncinate process, middle turbinate & middle meatus
Growth	Grows backwards to the choana; may hang down behind the soft palate	Mostly grow anteriorly and may present at the nares
Size & Shape	Trilobed with antral, nasal and choanal parts. Choanal part may protrude through the choana and fill the nasopharynx, obstructing both sides	Usually small and grape-like masses
Recurrence	Uncommon, if removed completely	Common
Treatment	Polypectomy; Endoscopic removal or Caldwell-Luc operation if recurrent	Polypectomy; Endoscopic surgery or ethmoidectomy (which may be intranasal, extranasal or transantral)