Huge Tracheal Diverticulum in a Patient with Mounier-Kuhn Syndrome

Tracheal diverticulum is a rare benign entity. Tracheobronchomegaly (TBM), also known as Mounier-Kuhn syndrome, is a rare disorder characterized by marked dilation of the trachea and main bronchi, associated with thinning or atrophy of the elastic tissue. Because of the weakened trachea and increased intraluminal pressure related to chronic cough, some patients may develop mucosal herniation leading to tracheal diverticulosis. We report the case of a patient with TBM with a huge tracheal diverticulum, diagnosed by bronchoscopy and computed tomography with three-dimensional reconstruction. to our knowledge this is the largest tracheal diameter described in a patient affected by this syndrome. LEARNING POINTS: Tracheal diverticulum is a rare condition that should be considered in the presence of bronchopulmonary disorders characterized by chronic cough and repeated bronchial infection, such as Mounier-Kuhn syndrome. The differential diagnosis of tracheal diverticulum includes laryngocele, pharyngocele, Zenker’s diverticulum, apical lung hernia and lung bullae. Bronchoscopy and CT scans with three-dimensional reconstruction are useful tools for diagnosing this rare condition.