结直肠锯齿状病变发病情况及其恶性潜能的病理学观察

Serrated lesions of colon and their malignant potential

目的分析结直肠锯齿状病变发生情况，并对锯齿状腺瘤与普通腺瘤的恶性潜能进行病理学比较观察。方法收集北京军区总医院、海军总医院、解放军第二五二医院、河北省巨鹿县医院、北京中医药大学东直门医院约5年中病理诊断为结直肠各类息肉和腺瘤的病例5347例，进行回顾性分析，经3名病理医师4—5轮阅片从中筛选出腺体具有锯齿状特征的息肉及腺瘤共258例，按文献标准分类，观察传统锯齿状腺瘤（TSA）及普通腺瘤异型增生程度。随机收集普通腺瘤（管状腺瘤160例及绒毛管状腺瘤27例）187例，浸润性腺癌36例作为对照。对部分TSA、广基锯齿状腺瘤（SSA）、管状腺瘤、浸润性腺癌进行免疫组织化学（MaxVision法）Ki-67、p53、B—e^enin染色。结果五所医院的5347例结直肠息肉／腺瘤中共筛选出锯齿状病变258例，占4．8％。其中增生性息肉（HP）112例，占锯齿状病变43．4％（112／258）；TSA78例，占锯齿状病变30．2％（78／258）；SSA26例，占锯齿状病变10．1％（26／258）；锯齿状病变合并高级别黏膜内肿瘤及浸润性腺癌11例，占锯齿状病变4．3％（11／258）。重点观察62例TSA的异型增生等级。62例TSA呈中度异型增生13例，高级别黏膜内肿瘤4例，浸润性腺癌癌旁有TSA成分2例。中度以上异型增生占30．6％（19／62），高级别黏膜内肿瘤和浸润性腺癌占9．6％（9／62）。收集的普通腺瘤187例，其中中度异型增生27例，高级别黏膜内肿瘤12例，13例在不同部位伴有浸润性腺癌，中度以上异型增生占27．8％（52／187），高级别黏膜内肿瘤和浸润性癌占13．3％（25／187）。TSA与普通腺瘤比较）（z=19．373，P=0．000。北京军区总医院19个月期间结直肠同时、不同部位具有锯齿状腺瘤及普通腺瘤13例（管状或绒毛管状腺瘤），其中锯齿状腺瘤13例中12例呈轻度异型增生，1例呈轻一中度异型增生；13例管状腺瘤中7例呈轻度异型增生，2例呈轻-中度异型增生，4例呈中度异型增生（两者相比x2=5．432，P=0．052）。对两组病例进行了Ki-67、p53、p—catenin检测，在锯齿状腺瘤（TSA、SSA）和普通腺瘤（管状）中的表达差异无统计学意义（P〉0．05），但锯齿状腺瘤与腺癌表达差异有统计学意义（P=0．000）。结论结直肠锯齿状病变发病率似较低。锯齿状腺瘤有明显恶性潜能。与普通腺瘤相比，锯齿状腺瘤合并高级别黏膜内肿瘤及浸润性癌的病例有所减少。

Objective To study the serrated lesions of colon and to compare the malignant potential between traditional serrated adenomas （TSA） and conventional adenomas （CAD）. Methods A total of 5347 cases of colorectal polyps encountered in five regional hospitals during a five-year period were retrospectively reviewed. The serrated lesions were classified on the basis of histologic examination. One hundred and eighty-seven cases of CAD （including 160 cases of tubular adenoma and 27 cases of villous adenoma） and 36 cases of invasive adenocarcinoma were randomly selected as the controls. The degree of dysplasia and expressions of Ki-67, p53 and beta-catenin in TSA and CAD were compared. Results Amongst the 5347 colorectal polyps studied, 258 cases （d. 8% ） of serrated lesions were found, which included 112 cases （43.4% ,112/258） of hyperplastic polyp, 78 cases （30. 2% ,78/25g） of TSA and 26 cases （10. 1%, 26/258 ） of sessile serrated adenoma. Sixty-two cases of TSA were identified from 3 hospitals, in which moderate dysplasia was found in 13 cases. High-grade intraepithelial neoplasia and ICA were found in 6 cases （9. 6% ）. Compared with the 187 cases of CAD, moderate dysplasia were found in 27 cases and high-grade intraepithelial neoplasia and invasive adenocarcinoma were found in 25 cases （ 13. 3% , X2 = 19. 373, P = 0. 000）. There was statistically significant difference between TSA and CAD in the degree of dysphasia. The expression of Ki-67, p53 and beta-catenin in TSA and CAD showed no significant difference （P 〉 0. 05 ）. Conclusions The incidence of serrated lesions is lower in northern Chinese population than that in Caucasians. TSA has obvious malignant potential; but the rate associated with high- grade intraepithelial neoplasia and invasive adenocarcinoma is lower than that in CAD.