Cholesterol granuloma in an antrochoanal polyp. A rare lesion in children.

Antrochoanal polyps (ACPs) are an infrequent clinical entity. Cholesterol granulomas (CGs) are commonly associated with chronic middle ear disease but are rare in the paranasal sinuses. We describe a case of a 10-year-old girl with a concomitant CG in an ACP which was surgically excised by nasosinusal endoscopic surgery. To our knowledge, there are only five previously published cases of CGs in ACPs and of these, only two were pediatric cases. We describe a third case in the youngest patient yet reported. Increased intrasinus pressure may affect venous and lymphatic drainage, leading to hemorrhages with hemolysis and deposition of cholesterol crystals and their esters initiating the formation of granulomas in the polyp. In addition, the insufficient lymphatic drainage prevents the complete elimination of lipids, contributing to the formation of cholesterol granulomas. The treatment and the outcome of an ACP associated with a CG are the same as for usual ACPs.