Unusual radiologic manifestations of bronchogenic cyst.

We have presented four cases of bronchogenic cyst, emphasizing the uncommon radiologic manifestations, including air trapping and/or lobulated contour. Two of the cysts were in the lung parenchyma, one in the left hilum adherent to the left lower lobe bronchus, and one in the posterior mediastinum. Recognition of the unusual radiologic features aids in establishing an appropriate differential diagnosis and directing subsequent evaluation.