[Chest X-ray image findings of Mycobacterium avium complex (MAC) lung disease].

Recently Mycobacterium avium complex (MAC) lung disease has increased in number remarkably in Japan. The MAC lung disease is divided into four types: a nodular bronchiectatic disease, a fibrocavitary disease, a hypersensitivity like disease, and a disseminated disease. Since the latter two types are rare, it is important in the diagnosis and treatment to understand the images of the former two. Formerly the fibrocavitary disease was more common, which occurred in the preceding tuberculous lesion frequently and showed images similar to tuberculosis. But recently the nodular bronchiectatic disease has increased in number particularly. Characteristic feature of this type is involving the right middle lobe and left lingual segment overwhelmingly in nonsmoking, immunocompetent, middle-aged women. Common CT manifestations of the nodular bronchiectatic disease include nodules just beneath the pleura, consolidation including bronchiectasis, and, lung volume shrinkage.