Thoracic sequelae and complications of tuberculosis.

Pulmonary tuberculosis is caused by Mycobacterium tuberculosis when droplet nuclei laden with bacilli are inhaled. In accordance with the virulence of the organism and the defenses of the host, tuberculosis can occur in the lungs and in extrapulmonary organs. A variety of sequelae and complications can occur in the pulmonary and extrapulmonary portions of the thorax in treated or untreated patients. These can be categorized as follows: (a) parenchymal lesions, which include tuberculoma, thin-walled cavity, cicatrization, end-stage lung destruction, aspergilloma, and bronchogenic carcinoma; (b) airway lesions, which include bronchiectasis, tracheobronchial stenosis, and broncholithiasis; (c) vascular lesions, which include pulmonary or bronchial arteritis and thrombosis, bronchial artery dilatation, and Rasmussen aneurysm; (d) mediastinal lesions, which include lymph node calcification and extranodal extension, esophagomediastinal or esophagobronchial fistula, constrictive pericarditis, and fibrosing mediastinitis; (e) pleural lesions, which include chronic empyema, fibrothorax, bronchopleural fistula, and pneumothorax; and (f) chest wall lesions, which include rib tuberculosis, tuberculous spondylitis, and malignancy associated with chronic empyema. These varieties of radiologic manifestations can mimic other disease entities. Therefore, recognition and understanding of the radiologic manifestations of the thoracic sequelae and complications of tuberculosis are important to facilitate diagnosis.