Unusual presentation of a large tension bronchogenic cyst in an adult.

A routine chest radiograph in a 20 year old man revealed a giant air filled cavity of the left hemithorax under tension. At thoracotomy a large left lower lobe intraparenchymal cyst required lobectomy and the pathological findings were consistent with a bronchogenic cyst. Although tension bronchogenic cysts are common in infants, this case demonstrates their unusual presentation in an adult.