Chronic Bronchitis

Chronic bronchitis

Mucous gland hyperplasia, the histologic correlate of chronic bronchitis is defined as a seromucous gland to wall thickness greater than 1/3. In this case the seromucous gland thickness (arrows) is more than 1/2 of the distance between the perichondrium and the epithelial basement membrane. Note also the goblet cell hyperplasia in the epithelium. The normal percentage of goblet cells is 20%.

Small airways disease

In patients with chronic bronchitis/emphysema, lumens of small airways may be distorted and narrowed by mural smooth muscle hyperplasia, fibrosis, or chronic inflammation and by luminal exudate or mucus. In emphysema, airways tend to collapse because of the loss of alveolar wall supports, as seen here. Mural inflammation and luminal exudate are also shown.