Figure 1. Plaque oral lichen planus. This area on the right buccal mucosa was biopsied and found to show typical features of oral lichen planus and no neoplasia. The patient was treated with three cryosurgery sessions.

Figure 2. Same patient shown in Figure 1. He did not come for the recommended consultations, returning 2 years later. The oral lichen planus evolved into squamous cell carcinoma. The right buccal mucosa shows an infiltrated and vegetating area.