Air-filled, multilocular, bronchopulmonary foregut duplication cyst of the mediastinum. Unusual computed tomography appearance.

Mediastinal bronchopulmonary foregut duplication cysts are usually identified on computed tomography (CT) as well-defined masses of water density that may contain rim calcification. Occasionally they are heterogenous in attenuation or are of intermediate or high attenuation due to contained calcium. Communication with the tracheobronchial tree or esophagus is rare. We report a bronchogenic cyst that communicated with the trachea and was identified by CT as a multilocolor, completely air-filled cyst adjacent to the trachea and esophagus. This appearance of a bronchogenic cyst has received little attention in the literature.