Pneumocele of the maxillary sinus. A second case report.

The term pneumocele refers to an expansile bone destructive air containing cyst-like lesion involving the sinus cavity proper, presumably due to obstruction of the major sinus ostium. It differs from pneumoceles described previously that have all been air pockets beyond a paranasal air sinus due to an abnormal fistulous communication, rather than expansion of the sinus cavity itself. In adding this second case to the literature we believe that this rare lesion may be encountered from time to time, and should be considered when an expanded maxillary antrum is found to contain air rather than fluid or soft tissue content.