Bilateral antrochoanal polyps: possible pathogenesis.

Antrochoanal polyp is a rare, benign solitary mass that arises from maxillary sinus. It exits through sinus ostium, passes across the middle meatus, and reaches into the choana. In general, it represents up to 6% of all nasal polyps. Although it is usually unilateral, in extreme rare cases it could be bilateral.We herein report a case of an 11-year-old girl who presented with bilateral antrochoanal polyps and was managed successfully by endoscopic surgical approach. We also hypothesize a possible pathophysiologic explanation of this rare disease.