AIMS

To assess the prevalence of malignant transformation of atypical lichen planus in our medium and describe the clinico-pathological features of the cases that had a premalignant potential.

MATERIALS AND METHODS

we performed a retrospective analysis of the records of patients seen at the Stomatology Department of the School of Dentistry, University of Buenos Aires, during the period 1991-1997. A total of 719 patients (7.02%) had oral lichen planus (481 women and 238 men). From a clinico-pathological point of view, 228 (31.7%) were typical forms and 491 (68.3%) were atypical forms. In all of the cases, lichen planus was confirmed histologically and a clinical protocol was followed.

RESULTS

Thirty-two (6.51%) patients were known to have developed malignant changes. In these cases the lesions had been diagnosed as atypical lichen planus at the outset. The most frequent clinical presentations were the keratotic (plaque-like) and erosive forms. Most of the lesions were on the tongue. The results support a premalignant potential for atypical lichen planus.

CONCLUSION

Oral lichen planus is a precancerous condition. The atypical form, particularly in its keratotic and erosive presentations, has a premalignant potential in our medium. The most frequent localization is the tongue.