Fig. 1.

K19 immunostain in normal epithelium and OED groups. Objective lens magnification of ×10, and resolution of 1.10 μm. a Normal epithelium showing intermittent cytoplasmic staining of the basal cell layer. b Mild epithelial dysplasia, showing continuous intense cytoplasmic staining of the basal cell layer. c Moderate epithelial dysplasia showing continuous intense cytoplasmic staining of the basal and suprabasal cell layers with occasional positive cells in the middle third of the surface epithelium. d Severe epithelial dysplasia showing intense cytoplasmic staining of the entire epithelial thickness