正常上皮由增生开始到发展为恶性肿瘤,一般要经过一个量变到质变的过程,即由正常上皮→不典型增生(或有异型性的角化病)→原位癌(恶性变),其中包括一个癌前病变阶段。80年代以来,癌前病变的研究已渐成为癌症研究的重点。研究这些病变特别是其如何转变为恶性肿瘤,在理论上和实践中都有重要意义。 The normal epithelium begins with hyperplasia and develops into a malignant tumor. It usually undergoes a process of quantitative change to qualitative change from normal epithelial to atypical hyperplasia (keratosis with atypical) to carcinoma in situ (malignant transformation), including A precancerous stage. Since the 1980s, the study of precancerous lesions has gradually become the focus of cancer research. The study of these lesions, especially how they are transformed into malignant tumors, is of great significance both theoretically and practically.