The efficacy of imiquimod on dysplastic lesions of the oral mucosa: an experimental model.

AIM: To study the potent efficacy of the immunomodulatory agent imiquimod when applied on dysplastic lesions of the oral mucosa. MATERIALS AND METHODS: Carcinogen (DMBA) was applied to the mucosa of the left buccal pouch of 26 male Wistar rats for 8 weeks, until dysplastic lesions were observed and histologically diagnosed. At the second phase of the experiment, 5% imiquimod cream was applied to these dysplastic lesions for 16 weeks. Biopsies were taken before and after treatment. RESULTS: The histological effect of imiquimod was the regression of mild dysplasia to hyperplasia for all the samples. In one case, a well-differentiated squamous cell carcinoma was converted to a papilloma-like squamous neoplasm with a benign morphology. CONCLUSION: Our results indicate that imiquimod may be effective in treatment of precancerous lesions of the oral mucosa and thus inhibit the progress of carcinogenesis.