Fig. 1
From: Airway smooth muscle as an underutilised biomarker: a case report
caption a: section of the endobronchial biopsy showing bronchial epithelial lining (black arrow head) with underlying marked subepithelial basement membrane thickening (white arrow) and smooth muscle hypertrophy (black arrow). Haematoxylin and eosin (H&E) stain, 200x magnification. b: Trichrome stain of the endobronchial biopsy highlighting the thickened subepithelial basement membrane (blue dye, white arrow). Also shown is squamous metaplasia of the bronchial epithelial lining (black arrow head) and underlying smooth muscle bundles (black arrow). 200x magnification