Clinicopathological features and malignant transformation of oral lichen planus: a 12-years retrospective study.

OBJECTIVE: Oral lichen planus (OLP) is known to be associated with the risk of developing oral squamous cell carcinoma (OSCC). The objective of this study was to investigate the clinicopathological features of OLP and the prevalence of malignant transformation in this setting.

MATERIALS AND METHODS: This retrospective study was carried out on 204 medical records of patients with histologically proven OLP who received long-term follow-up (range 6 months-12 years). Data were entered in an informatic database. The statistical analysis, when needed, was performed with the chi-squared test for significance (p < 0.05).

RESULTS: At the moment of the diagnosis, out of 204 patients (163 female and 41 male; mean age 54.5 years), 107 patients (52.45%) suffered from systemic chronic diseases, in particular 46 (22.5%) from hepatitis C. Clinically, the reticular form of OLP was the predominant one and most patients had multiple oral sites of involvement. Fourteen patients showed extra-oral lesions. A percentage of malignant transformation less than 1% was found. In fact, two patients (0.98%) underwent a malignant transformation at a site previously diagnosed as OLP.

CONCLUSIONS: At present, OLP is accepted as being a potential malignant disorder, therefore lifelong follow-up is recommended.