Fig. 2

Histopathological features of small airways disease in COPD. a A COPD bronchiole with a thickened airway wall due to fibrotic remodeling and excessive deposition of collagen bundles (blue colouration). Section stained with Masson’s Trichrome (10X magnification). b A COPD bronchiolevascular bundle whereby the bronchiole contains a large intra-luminal mucous plug (red arrow) (2X magnification). Section stained with hematoxylin and eosin. c A COPD bronchiole with increased numbers of goblet cells (greenarrows) in the epithelial lining (20X magnification). Section stained with hematoxylin and eosin. d The wall of a COPD bronchiole with increased numbers of inflammatory cells (black arrows) (20X magnification). Section stained with hematoxylin and eosin