Antrochoanal polyps in children: CT findings and differential diagnosis.

Antrochoanal polyp (Killian polyp) is an infrequent, usually solitary, benign, slowly growing lesion that arises from the maxillary antrum and reaches the choana. These polyps have a discrete male predominance and are diagnosed usually between the third and the fifth decades of life. This report is based on three cases of antrochoanal polyp, occurring in the pediatric group, and the objective is to demonstrate their different CT characteristics, principal differential diagnoses, and potential complications. We emphasize that in all three cases of our series the growth of the polyp to the choana is through the accessory ostium.