LearningRadiology - Bronchogenic Cysts

Congenital 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

X-r ay

• 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

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