Pneumosinus dilatans of the ethmoid sinus--incidental finding on a cephalometric radiograph.

A case of pneumosinus dilatans of the posterior ethmoidal region is presented. The condition known as pneumosinus dilatans is discussed, as are accessory ethmoidal air cells with respect to their most common localization and radiographic appearance. The diagnostic imaging features of this condition are described and a recommendation of views to adequately delineate this disorder are given. The importance of an adequate and thorough review of the cephalometric radiograph for pathologic conditions is stressed.