现在有三种病变——孤立性息肉、家族性息肉病和溃疡性结肠炎,值得考虑。只有病理诊断为腺瘤性息肉和乳头状腺瘤者,才是癌前病变。皆有上皮异常增生。癌变率和病变体积有关,在直径小于1厘米者中,很少发现早期浸润性癌,直径大干2厘米者中,约50%见癌。增生性或化生性息肉非癌前病变。腺瘤性息肉癌变 There are three types of lesions - isolated polyps, familial polyposis, and ulcerative colitis - which are worth considering. Only pathological diagnosis of adenomatous polyps and papillary adenomas is the precancerous lesion. All have epithelial dysplasia. The rate of canceration is related to the volume of lesions. Among those with a diameter of less than 1 cm, early invasive cancers are rarely found. About 20% of diameters are about 50% of cancers. Proliferative or metaplastic polyps are not precancerous lesions. Adenomatous polyposis