A quantitative cytological study of lesional and non-lesional mucosa in oral lichen planus

Smears of buccal mucosa, dorsal surface of the tongue and floor of mouth were taken from 10 patients with histologically confirmed oral lichen planus and 12 healthy age- and sex-matched controls. In buccal smears, no significant differences in cytoplasmic and nuclear areas were observed between lesional, adjacent non-lesional and control tissues. However, the cytoplasmic area in smears from lichen planus lesions on the dorsum of the tongue and adjacent clinically normal mucosa was reduced compared with healthy controls. The cytoplasmic: nuclear ratio in smears from clinically normal floor of mouth in oral lichen planus was similarly reduced. Papanicolaou-stained smears from buccal lichen planus showed increased keratinization compared with normal buccal mucosa. These findings demonstrate that quantitative cytology can detect both cytoplasmic and nuclear changes in oral lichen planus.