These
lesions clinically appear as thickened, plaque-like lesions of the
epithelium which show leukoplakia on the surface and increased vascularity(#21894).Pathologically, these lesions are characterized by dysplasia of the
squamous cells in the epithelium which involves its full-thickness
(#21895).This is in essence a carcinoma "in situ" and shows
preservation of the epithelial basement membrane with no invasion into the
underlying substantia propria (#21897).
