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

口腔白斑是一种癌前病变。但并不是所有的白斑都会发展成恶性，因此区分不同程度的恶性潜能白斑并不容易。本研究旨在寻找客观、定量评价白斑恶性潜能的有效措施。1)临床表现上，白斑的颜色与恶性潜能密切相关，有红色成分的白斑风险较高。据此，采用新型色度计在不接触物体的情况下测量舌白斑的颜色。测量的颜色用图形记录，与正常语言颜色的色差用CIE-LAB系统表示，即三维标准坐标（L^*a^*b^*）。一般情况下，白斑的值指数（L^*）高，色度指数（a^*, b^*）低。但就严重上皮发育不良的白斑而言，其出现的特殊颜色（L^*低，a^*高）即红色成分。2)组织病理学发现，口腔上皮细胞角蛋白（CK）表达模式与细胞分化水平有关。因此，免疫组织化学分析CK表达被认为有助于客观评价白斑的发育异常变化。CK10在角化过度的上皮中表达，CK13在轻度发育不良的白斑棘层中表达。但CK10和CK13在细胞异型程度增高的区域均不存在。CK高分子量基因（包括CK 1、5、10、14）在背脊不规则伸长区域表达强烈。CK19的表达通常仅见于基底层，但也见于严重发育不良的白斑的基底上细胞。

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.