大肠小扁平腺瘤的形态及病理组织学特征研究

The morphological and histopathological features of colorectal small flat adenoma

目的探讨大肠小扁平腺瘤的形态学特征及p53、p21、雌激素受体(estrogen receptor, ER)、孕激素受体(progesterone receptor,PR)表达的生物学意义。方法用Olympus CF240型电子结肠镜及Olympus BX41光学显微镜观察50例大肠小扁平腺瘤形态学特征。用免疫组化二步法检测50 例小扁平腺瘤及其腺瘤旁组织、26例大肠癌及其癌旁组织、15例正常人大肠黏膜中p53、p21、ER、PR 的表达情况。结果小扁平腺瘤发生于大肠任何部位,其发病率依次以横结肠、乙状结肠、直肠为多见;肠镜下见病灶呈圆形或椭圆形,扁平状,基底宽,体积≤1cm。光镜下小扁平腺瘤呈管状腺瘤样图像,上皮具有不同程度的异型增生。小扁平腺瘤中p53、p21、ER、PR的表达率分别为58%(29/50)、56%(28/50)、12%(6/50)、10%(5/50)。随着小扁平腺瘤异型增生程度的增高,p53、p21、ER、PR的表达率也逐渐升高(P<0.05)。大肠癌中的表达最高(P<0.05)。结论大肠小扁平腺瘤有其独特的形态学特征,p53、p21、ER、PR的表达与大肠小扁平腺瘤的发生发展有密切关系。

Objective To be investigated the morphology of colorectal small flat adenoma and the expressions of p53, p21, ER and PR. Methods Colonoscopy（ Olympus CF 240） and microscopy（ Olympus BV 41 ） were used to observe 50 cases of colorectal small flat adenomas. The expressions of p53, p21, ER, and PR were detected by the two steps of immunohistochemistry in 50 cases of small flat adenomas and the surrounding mucosa, 26 cases of colorectal carcinomas, while 15 cases of the normal colorectal mucosa as control group. Results These lesions were distributed throughout the large bowel, the prevalence in order was transverse colon, sigmoid and rectum. The small flat adenoma was round, flat, or sessile in shape, and sized 〈 10mm in diameter. Small flat adenoma is tubular adenoma-like features with varying degrees of dysplasia under light microscopy. The expressions of p53, p21, ER and PR in small flat adenomas were 58% （29/50）, 56% （28/50）, 12% （6/50） and 10% （5/50） respectively. With the increasing degree of dys- plasia, the expressions of p53, p21, ER and PR were increased in small flat adenomas （P 〈0. 05）, and it is the highest in colorectal carcinomas （ P 〈 0. 05 ）. Conclusion Small flat adenomas show their distinct colonoscopic and histological characteristics. The expressions of p53, p21, ER and PR were closely associated with the pathogenesis of small flat adenomas.