All are true about Antrochoanal polyp, EXCEPT:

Antrochoanal polyp are benign lesions that are most commonly seen in children. This isolated polyp has its origin from the mucosa of the maxillary sinus and extend into choana and nasopharynx. The major problem is unilateral nasal obstruction. Treatment of choice is primary endoscopic removal with resection of the basis in the maxillary sinus. Complete removal of the polyp's base is mandatory to prevent a recurrence.