Bronchogenic Cysts
Bronchial Cysts

• Primitive foregut gives rise to both the esophagus (dorsal segment) and the tracheobronchial tree (ventral segment).

• Bronchial cysts result from abnormal budding of the ventral segment of the foregut [Failure of the solid core of the esophagus to cannulate produces esophageal duplications and abnormalities of the dorsal segment produce neurenteric cysts].

• More common in males and Yemenite Jews

• Bronchial cysts form in the first trimester of pregnancy

• They may be either mediastinal, parenchymal or, sometimes, infradiaphragmatic

            • Mediastinal

                        • More common

                        • Occur around carina

                        • May be associated with spinal abnormalities

                        • Are usually asymptomatic

            • Parenchymal

                        • Much less common

                        • Usually occur in the lower lobes

                        • Become infected and thus contain air

                        • May present with hemoptysis

• Most common type of mediastinal cyst in an infant

• They do not communicate with the tracheobronchial tree unless infected

Imaging

• Most are mediastinal and occur around the carina, upper trachea or along bronchi.

• Occur in middle mediastinum

• Almost all are fluid-filled and appear as solid, well-defined, sharply-marginated mass

• Rarely, they may contain milk of calcium