Mounier-Kuhn syndrome in poorly controlled asthma.

Mounier-Kuhn syndrome or tracheobronchomegaly, is a rare condition that consists of abnormal dilation of the trachea and main bronchi due to a pathological arrangement of smooth muscle fibers in this area. We present the case of a 46-year-old woman with poorly controlled asthma and recurrent infections, who was diagnosed with Mounier-Kuhn syndrome through a computed tomography scan revealing an unusual enlargement of the trachea with associated bronchiectasis. The diagnosis of Mounier-Kuhn syndrome is radiological, involving measurement of the trachea where a diameter >25 mm in men and >21 mm in women is observed. While diagnosis is sometimes incidental, there is an association with respiratory diseases such as asthma or COPD, hence clinical suspicion is important in patients with poorly controlled underlying conditions who present with recurrent infections, inadequate secretion management, or even hemoptysis. Despite its rarity, this syndrome significantly impacts patients' quality of life. Diagnosis and management involve comprehensive evaluations including computed tomography, with a multidisciplinary approach including pulmonologists and radiologists. Exploring its clinical features, associations with other respiratory diseases and treatment options is crucial in managing this rare respiratory condition.