Unusual presentations of choanal polyps: report of 3 cases.

Most choanal polyps arise from the maxillary sinus, and they are called antrochoanal polyps. Their typical endoscopic and radiologic appearance makes them easy to diagnose. However, some choanal polyps originate in unusual sites in the paranasal sinuses and nose, such as the sphenoid sinus and the lateral wall of the nose. These polyps usually present unilaterally, although bilateral presentations are possible. We describe 3 cases of atypical choanal polyps: a sphenochoanal polyp, bilateral antrochoanal polyps, and a giant antrochoanal polyp. In each case, nasal endoscopy and computed tomography clinched the diagnosis, and endoscopic surgery was performed to successfully remove the polyp. We discuss the clinical characteristics of these 3 cases.