Uncinate Atelectasis

The first image was obtained four months prior to the remaining five images. It shows a clear right maxillary sinus, but opacification of the left maxillary sinus, widening of the left maxillary antrum, and opacification of the left nasal cavity by a mass which was found to be an inverted papilloma. On the subsequent CT following resection of this mass, the right maxillary sinus is completely opacified with concavity of the maxillary sinus wall, occlusion of the infundibulum, and lateralization of the uncinate. This is inward bowing is indicative of negative pressure and reflects uncinate atelectasis. This may result in enophthalmos and so-called silent sinus syndrome with possible diplopia. The differential diagnosis includes maxillary sinus hypoplasia.