[Bronchogenic Cyst with Rapid Increase and Emergency Operation;Report of a Case].

A 21-year-old man was admitted with fever and back pain. Chest computed tomography(CT) showed a cystic mass of 7×6 cm in the right middle mediastinum. After 3 days, symptoms worsen, and chest X-ray revealed the enlargement of the cyst, and an emergent operation was performed. Since the tumor was severely adhered to the superior vena cava and the azygous vein, the cystic mass was partially resected. The pathological diagnosis was bronchogenic cyst.