Histopathologic study of lichen planus shows:

Histologic features of lichen planus include: Saw, tooth appearance of retepegs Liquefaction degeneration of basal layer which is replaced by thin band of eosinophilic coagulum Presence of civatte bodies Characteristic band Like subepithelial mononuclear infiltrate consisting of T- lymphocytes and histiocytes sharply limited to papillary and most superficial portion of the reticular layers of connective tissue Hyperparakeratosis or hyperorthokeratosis Thickening of granular layer