title: Bronchiolitis. Pathologic considerations.
abstract: Bronchiolitis represents a cellular and mesenchymal reaction involving bronchioles. The interplay between the cellular infiltrate and the mesenchymal reaction affects the lumen size, lamina propria, muscular layer, and bronchiolar adventitia. The result is a variety of clinical, radiologic, and functional patterns of bronchiolar disease. The anatomy of the small airways is discussed, and a pathologic classification applicable to the surgical pathology of bronchiolitis is presented. The classification is practical and includes asthma, chronic obstructive pulmonary disease, cellular bronchiolitis, respiratory bronchiolitis, respiratory bronchiolitis-associated interstitial lung disease, bronchiolitis obliterans (including bronchiolitis obliterans with intraluminal polyps and constrictive bronchiolitis), dust-related small airway fibrosis, and (postinflammatory) bronchiolar scarring and peribronchiolar fibrosis.
authors.affiliation: Department of Pathology, Mayo Clinic Scottsdale, Arizona, USA.
authors.forename: T V
authors.initials: TV
authors.lastname: Colby
mesh_terms: D001249:Asthma / Q000473:pathology; D001980:Bronchi / Q000033:anatomy & histology / Q000473:pathology; D001988:Bronchiolitis / Q000276:immunology / Q000473:pathology*; D001989:Bronchiolitis Obliterans / Q000473:pathology; D002675:Child, Preschool; D018549:Cryptogenic Organizing Pneumonia / Q000473:pathology; D005355:Fibrosis / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D008173:Lung Diseases, Obstructive / Q000473:pathology; D008679:Metaplasia / Q000473:pathology