tracheobronchomegaly tracheobronchomegaly tracheobronchomegaly is a very rare congenital disorder of the lung primarily characterized by an abnormal widening of the upper airways. the abnormally widened trachea and mainstem bronchi are associated with recurrent lower respiratory tract infection and copious purulent sputum production, eventually leading to bronchiectasis and other respiratory complications. tracheobronchomegalyother namesmounier-kühn syndromespecialtypulmonology complicationsrecurrent pulmonary infectionscausesatrophy of elastic fibers in the trachea and main bronchi, leading to thinning of the smooth muscle layerdiagnostic methodct chest. tracheobroncheal flaccidity, dilatation, and/or collapse.frequency300 cases have been reported to date diagnosis woodring et al. (1991) suggested the following diagnostic criteria for tracheomegaly in adults based on chest radiography: adult males: tracheal transverse diameter > 25 mm and sagittal diameter > 27 mm. adult females: tracheal transverse diameter > 21 mm and sagittal diameter > 23 mm. history the term "mounier-kuhn syndrome" derives from the characterization of the condition by prof. pierre-louis mounier-kuhn in 1932, while the name "tracheobronchomegaly" was introduced by katz et al. in 1962.