Chromatological and immunohistochemical study of oral premalignant lesions-Evaluation of mailgnant potentiality-

口腔白斑是一种癌前病变。但并不是每个白斑都会发展为恶性，而且不一定很容易区分具有不同程度恶性潜能的白斑。本研究旨在寻找客观、定量评价白斑恶性潜能的有效方法。1)从临床表现来看，白斑的颜色与恶性潜能密切相关，红色成分的白斑具有较高的危险性。因此，用新型比色仪测量舌白斑的颜色，而不接触物体。测量的颜色用图形记录，与正常舌色的色差用CIE-LAB系统，三维标准坐标(L^*a^*b^*)表示。白斑一般价值指数(L^*)较高，色度指数(a^*、b^*)较低。而对于重度上皮异型增生的白斑，其特有的颜色(L^*为低，a^*，b^*为高)即红色成分出现。2)组织病理学发现，细胞角蛋白(CK)在口腔黏膜上皮中的表达与细胞分化程度有关。因此，免疫组织化学分析CK的表达有助于客观评价白斑的异常增殖性改变。CK10在角化过度的上皮细胞表达，CK13在轻度不典型增生的白斑棘层表达。但CK10和CK13在细胞异型性增加的区域均缺失。CK高分子量包括CK 1、5、10、14，在网脊不规则伸长的部位有较强的表达。正常白斑中CK19的表达仅见于基底层，在重度异型增生的白斑中也可见基底层以上细胞表达。

Oral leukoplakia is known as a premalignant lesion. But every leukoplakia doesn't develop malignancy and it may not necessarily be easy to distinguish the leukoplakias with verious levels of malignant potentiality. The aim of this study was to find the effective measures to evaluate the malignant potentiality of leukoplakia objectively and quantitatively.1)As to clinical finding, the color of leukoplakia is closely connected with the malignant potentiality and the leukoplakia with red component has the higher risk. Accordingly the color of the lingual leukoplakia was measured with the new-type of colorimeter without touching the object. The measured color was recorded in figures and the color difference from the normal lingual color was expressed in CIE-LAB system, the three-dimentional standard coordinates (L^*a^*b^*). In general value index (L^*) is high and chromaticness index (a^*, b^*) is low in leukoplakia. But so far as leukoplakia with severe epithelial dyspasia is concerned, the peculiar color (L^* is low and a^*, b^* is high) namely red component made its appearance.2)Concerning histopathological finding, the cytokeratin (CK) expression pattern in oral epithelium is related to the cellular differentiation level. Therefore immunohistochemical analysis of CK expression was thought to be useful aid for the objective evaluation of dysplastic change in leukoplakias. CK10 expression was seen in the epithelium with hyperorthokeratosis and CK13 in the stratum spinosum of the leukoplakia with slight dysplasia. But both CK10 and CK13 were absent in areas with increased degree of cellular atypia. CK high molecular weight, whict includes CK 1,5,10,14, was expressed strongly in the areas where the rete ridge showed irregular elongation. Expression of CK19 was normally seen only in the stratum basale, but also in suprabasal cells in the leukoplakia with severe dysplasia.