MIDDLE LOBE SYNDROME

Middle lobe syndrome is defined as recurrent or chronic collapse of th e middle lobe of the right lung. It occurs in all age groups and is di vided into an obstructive type, with a demonstrable airway occlusion, and a nonobstructive type, with a patent right middle robe bronchus ap parent on bronchoscopy. Middle lobe collapse has specific radiographic findings. Malignancy is the most common cause of the obstructive type , and infections are the second leading etiology. The nonobstructive t ype is associated with inflammatory conditions and bronchiectasis. In all cases, treatment is directed at the underlying cause.