[Clinicopathological characteristics of malignant transformation in 85 cases of oral leukoplakia].

OBJECTIVE: To investigate the histological features of oral leukoplakia which underwent malignant transformation and its correlation with the clinical manifestation. METHODS: A total of 1832 cases of oral leukoplakia were reviewed and the clinicopathological characteristics of malignant transformation were analyzed. RESULTS: Malignant transformation occurred in 85 cases (4.6%) of the 1832 cases. Thirty cases (2.1%) of 1404 cases with simple epithelial hyperplasia had malignant transformation. Fifty-five cases (12.9%) in 428 cases with epithelial dysplasia were transformed to malignancy, especially in the cases with moderate or severe dysplasia, in which the ratio of malignant transformation was higher than in the cases with simple epithelial hyperplasia (P < 0.005). Clinical parameters associated with an increased risk of malignant transformation were female gender and epithelial dysplasia was more often seen in non-homogenous leukoplakias than in homogenous (P < 0.005). CONCLUSIONS: Non-dysplastic leukoplakia may become malignant. Epithelial dysplasia was associated with an increased risk of malignant transformation. Leukoplakia in female may be at a higher risk for malignant transformation.