Broncholithiasis: review of the causes with radiologic-pathologic correlation.

Broncholithiasis is defined as a condition in which calcified or ossified material is present within the bronchial lumen. Radiographic findings of broncholithiasis include airway obstruction such as atelectasis, mucoid impaction, bronchiectasis, and expiratory air trapping. Broncholithiasis is strongly suggested at computed tomography (CT) when an endobronchial or peribronchial calcified nodule is associated with findings of bronchial obstruction. Volume data acquisition by means of helical CT with sections less than 3 mm in thickness and multiplanar reformation along the bronchial tree are helpful in confirming the endobronchial location of the calcified material. The most common cause of broncholithiasis is erosion by and extrusion of a calcified adjacent lymph node into the bronchial lumen, a finding usually associated with tuberculosis or histoplasmosis. Other causes of broncholithiasis include (a) aspiration of bone tissue or in situ calcification of aspirated foreign material and (b) erosion by and extrusion of calcified or ossified bronchial cartilage plates. Primary endobronchial infections with dystrophic calcification, calcified endobronchial tumors, tracheobronchial diseases with mural calcification, and hypertrophied bronchial artery with intramural protrusion may mimic broncholithiasis. An awareness of the typical imaging findings of broncholithiasis, along with a knowledge of its various causes, help in establishing an accurate diagnosis to ensure proper case management.