[Specific notch in early expiration region of a flow-volume curve in a case of Mounier-Kuhn syndrome].

A 75-year-old man presented at our hospital for evaluation of a chronic cough and sputa. Radiographic examination showed enlargement of the trachea and main bronchi. On chest radiography, the transverse diameter of the trachea was 39 mm at the level of the third thoracic spine. On bronchoscopy, the trachea and main bronchi were dilated on inspiration and were completely collapsed on expiration. A 3-D CT examination showed the trachea and main bronchi dilated, and the cartilage of the trachea and bronchi distorted. In pulmonary function testing, this disorder is characterized by the appearance of a specific notch in the early phase of expiration on the flow-volume curve.