All of the following are true of antrochoanal polyp except
ExplanationC. Localised U/L nasal polyposis can occur following obstruction to the osteo-meatal complex due to anatomical variation (e.g. Haller cell, Concha bullosa, DNS, etc.). Though uncommon, when it involves only the maxillary sinus leading to the formation of single, U/L polyp, it is known as antrochoanal polyp. It is seen in young. The main aetiology of antrochoanal polyp is infection. Antrochoanal polyp arises from the maxillary antrum and as the name antro (antrum) choanal (posterior nares) it grows through the nasal cavity posteriorly into the choana and nasopharynx. Hence it is large and in spite of this it might not be visible on anterior rhinoscopy. It can be seen on posterior rhinoscopy. It can even hang down behind soft palate into oropharynx. Though it is unilateral but once the polyp grows into the nasopharynx it can cause bilateral nasal obstruction.
