Part 2 book “Pulmonary pathology - An atlas and text” has contents: Small airways, alveolar infiltrates, tobacco-related diseases, diffuse interstitial lung diseases, idiopathic interstitial pneumonias, specific infectious agents, transplant-related pathology, lung pathology in collagen vascular diseases, and other contents. | SECTION 12 Small Airways Sanja Dacic 820 CHAPTER 83 Bronchiolar and Peribronchiolar Inflammation, Fibrosis, and Metaplasia Sanja Dacic Small airways may be involved by inflammation and scarring either as an isolated or focal condition (., a scarred bronchiole from a prior focal infection) or as a widespread or diffuse process. Inflammation and scarring of bronchiolar walls and the adjacent alveolar septa may be accompanied by metaplasia of the bronchiolar or alveolar epithelium. The bronchiolar epithelium may undergo goblet-cell metaplasia or squamous metaplasia. The appearance of bronchiolar-type epithelium on the surface of fibrotic alveoli next to a scarred bronchiole is sometimes called lambertosis, which refers to an older concept that this epithelium grew onto the alveolar surface from the bronchiolar lumen via the canals of Lambert. Small airways may be a primary site of disease, or most frequently the scarring and inflammation are the result of secondary involvement such as in bronchiectasis or bronchopneumonia. Histologic Features ◾ Inflammation and scarring in the walls of bronchioles and in the alveolar septa adjacent to the bronchioles. 821 ◾ Goblet-cell metaplasia or squamous metaplasia of the bronchiolar epithelium. ◾ Bronchiolar metaplasia, goblet-cell metaplasia, or squamous metaplasia of the surface lining of adjacent scarred alveolar septa (lambertosis). Figure Small airway scarring extending into adjacent alveolar septa lined by metaplastic bronchiolar-type epithelium. 822 Figure Small airway submucosal scarring and prominent bronchiolar metaplasia (lambertosis) in the adjacent lung parenchyma. 823 Figure High-power magnification of .
