RÉSUMÉ
Objective To improve the diagnosis and differential diagnosis of mediastinal cysts.Methods 36 patients with mediastinal cyst proved by surgery and pathology were collected, and CT findings were analyzed retrospectively.Results In all 36 cases,CT defined the masses with clear margin, thin wall and fluid-like density content which had no enhancement after intravenous contrast administration. There were neurenteric cyst(n=1), bronchial cyst(n=12), esophageal cyst(n=2), pericardial cyst(n=5), dermoid cyst(n=7), lymphangioma(n=4), thymic cyst(n=4) and non-special cyst(n=1). Conclusion The diagnosis of mediastinal cyst and differential diagnosis from other cystic lesions can be made according to the characteristics on plain and post-contrast CT scans.