Bronchogenic Cysts Presenting as Thymic Cysts Although relatively rare, bronchogenic cysts are the most common of the cystic mediastinal masses. Because the majority will become symptomatic or complicated, bronchogenic cysts should be considered in differential diagnoses of mediastinal masses. Bronchogenic cysts most commonly occur in the middle or posterior mediastinum but have been reported throughout the thorax as well as in other atypical locations. We report the diagnosis and treatment of two extremely rare cases of bronchogenic cysts occurring within the thymus. Read More →