Tracheobronchomegaly (Mounier-Kuhn Syndrome): A Rare Cause of Recurrent Pulmonary Infections – Imaging Case Review

Mounier-Kuhn syndrome, or tracheobronchomegaly, is a rare congenital disorder caused by structural weakness of the tracheobronchial wall, leading to abnormal dilatation of the trachea and main bronchi. It predisposes patients to impaired mucociliary clearance, recurrent infections, and progressive pulmonary dysfunction. We present the case of a 40-year-old man with chronic productive cough and repeated episodes of lower respiratory tract infections resistant to standard medical therapy. Chest CT revealed marked dilatation of the trachea (>30 mm) and main bronchi (20 mm right, 18 mm left), associated with diffuse bronchiectasis, bronchial wall thickening, mucus plugging, and centrilobular micronodules. These findings were consistent with Mounier-Kuhn syndrome. Recognition of this entity is essential, as its clinical presentation is nonspecific, and diagnosis relies primarily on CT-based morphometric criteria. Management is supportive, focusing on infection prevention, prompt antibiotic therapy, and pulmonary physiotherapy.