Abstract
BACKGROUND: Bronchogenic cysts can be caused by errors in the growth of the ventral foregut. Localization of the bronchogenic cyst (BC) varies depending on the level of the abnormal budding. They are usually located in the lungs and mediastinum. BCs of the diaphragm are a rare form of this abnormality. CASE PRESENTATION: A 66-year-old woman coughs and expectorates. CT scan evaluation revealed a soft tissue shadow of 6 × 5 cm in the left lung. Under thoracoscopic surgery, we found that the mass originated from the diaphragm away from the lung tissue, we completely removed the mass and the pathological result was diagnosed as BC. CONCLUSIONS: The prognosis of ectopic BC is usually optimistic for benign tumors, as long as the tumor is completely removed.