[Histological classification of oral leukoplakia by a classification number].

From 1969 to 1980 the authors examined 587 histological specimens of oral leukoplakia obtained from 424 patients. The histological findings were assessed in classification numbers qualitatively and quantitatively characterizing the subepithelial inflammation, epithelial hyperplasia, keratosis, the grade of epithelial dysplasia an the degree of infiltration when carcinoma had already developed. From this histological classification a classification number resulted which allows conclusions on the prognosis of the leukoplakia under study. Besides the grade of dysplasia also the features of the subepithelial inflammation are important for the prognostic assessment of leukoplakia. The classification numbers are suitable for data processing. In the grading system reported, the most important morphological findings are represented with qualitative and quantitative objectiveness. The classification number leads to more reliable comparison and evaluation of the results obtained by different research groups.