Supradiaphragmatic Bronchogenic Cyst Extending Into the Retroperitoneum

We experienced a case of bronchogenic cyst located on the left lower pleural space extending into the retroperitoneum in a 33-year-old man with left chest pain. Preoperative imaging studies and operative findings showed a broad-based cystic mass on the left lower posterior pleura and diaphragmatic pleura extending into the retroperitoneal region across the diaphragm. Histologic studies proved this mass to be a bronchogenic cyst.