Possible premalignant character of oral lichen planus. The Amsterdam experience.

In the present paper the 21-yr experience of the Department of Oral and Maxillofacial Surgery and Oral Pathology, and the Department of Otorhinolaryngology of the Free University Hospital, Amsterdam, is reported with regard to the possible premalignant character of oral lichen planus. The study consists of two parts: 1) the follow-up of 113 patients with histopathologically proven oral lichen planus, and 2) a search for lichen planus in 727 patients who have been admitted for oral cancer. Three patients with histopathologically proven lichen planus developed a squamous cell carcinoma in an average follow-up period of 7 yr. In the 727 patients with oral cancer, two additional patients with the simultaneous occurrence of oral lichen planus were observed. Our experience gives some but not very strong support to the hypothesis that oral lichen planus is a premalignant condition.