COMPARISON OF PROLIFERATING CELL NUCLEAR ANTIGEN INDEX IN BENIGN AND MALIGNANT SALIVARY PLEOMORPHIC ADENOMA

The expression of proliferating cell nuclear antigen (PCNA) was studie d in benign and malignant pleomorphic adenomas by using monoclonal ant ibody to PCNA. Carcinoma in pleomorphic adenoma (n = 8), cell-rich var iant (n = 6) and typical pleomorphic adenoma (n = 6) were selected in this study. The PCNA index in carcinoma in pleomorphic adenoma showed a higher index of nuclear staining (mean 22.9%, S.D. 6.2) than in typi cal pleomorphic adenoma (mean 6.9%, S.D. 3.4) or a cell-rich variant o f pleomorphic adenoma (mean 8.8%, S.D. 3.3). A significant difference in PCNA index was found between benign and malignant pleomorphic adeno ma (P<0.05). The present study suggests that PCNA index significantly differs between pleomorphic adenoma and carcinoma in pleomorphic adeno ma, but in the prediction of malignant transformation potential it sho uld be combined with routine histopathological examination.