Results: There was also a high expression of Blc-2 protein in inflammatory cells in OLP lesions and leukoplakia with epithelial dysplasia. The expression of Ki-67 marker was higher in all analyzed tissue levels in the lesions of OLP and leukoplakia with epithelial dysplasia when compared with the control group. Objective: Pleomorphic adenoma (PA) is the most common benign salivary gland neoplasm of the major and minor salivary glands. Pleomorphic adenoma was shown sometimes to undergo malignant transformation in its natural course. Carcinoma ex pleomorphic adenoma (CPA) is a rare salivary gland malignancy that may develop from either a long-standing primary or a recurrent PA. The genetic mechanisms involved in the progression of adenoma to a carcinoma is still unclear.