结直肠锯齿状息肉报道

1、简要介绍锯齿状病变专家共识推荐规范 2010年在Cleveland举行，由美国胃肠病学 会(ACG)支持、美国国立卫生研究院(NIH) 赞助 专家组成员：endoscopy, surgery, pathology, epidemiology, and/or molecular aspects of serrated lesions and/or serrated polyposis. 经与会专家组讨论15年MEDLIAN文献，形 成共识报告，目的是总结锯齿状息肉病理 、分子病理和内镜特征，提高这种疾病威 胁的意识，描述内镜特征，强调该疾病精 确探查和完全切除的重要性，提供有关该 病切除后处理的

2、推荐规范。 Key conclusions and recommendations of the consensus group Pathology 1 Serrated lesions of the colorectum should be classified histologically as hyperplastic polyp (HP), sessile serrated adenoma/polyp(SSA/P) with or without cytologic dysplasia, or traditional serrated adenoma (TSA). Exceptions

3、 and subcategories are discussed in the text. Clinicians and pathologists within institutions should work collaboratively to achieve a common usage and understanding of terminology of serrated lesions. 2 SSA/P and TSA are pre-cancerous lesions. SSA/P is the principal precursor of hypermethylated col

4、orectal cancers (cancers with the CpG Island Methylator Phenotype CIMP). This pathway occurs primarily in the proximal colon. 3 SSA/P is distinguished from HP pathologically by findings of crypt distortion, particularly in the crypt base, in SSA/P. We recommend that a single unequivocal architectura

5、lly distorted, dilated, and/or horizontally branched crypt, particularly if it is associated with inverted maturation, is sufficient for a diagnosis of SSA/P. Most large serrated lesions in the proximal colon are SSA/Ps. 4 SSA/P with cytological dysplasia is a more advanced lesion in the progression

6、 to cancer compared to SSA/P without cytological dysplasia. Endoscopy 5 SSA/P and hyperplastic polyps in the proximal colon have a distinct endoscopic appearance, which includes a “mucus cap”, color usually similar to normal mucosa, and indistinct edges. All colonoscopists should be able to recogniz

7、e serrated lesions. 6 Detection of proximal colon serrated lesions by individual endoscopists is highly correlated with adenoma detection. Pending development of specific detection targets for proximal colon serrated lesions, endoscopists should measure their adenoma detection rates as a check on ad

8、equate detection of serrated lesions. 7 All serrated lesions proximal to the sigmoid colon should be fully resected during colonoscopy. All serrated lesions in the rectosigmoid colon 5 mm in size should be fully resected. Surveillance 8 Serrated polyposis is defined by the World Health Organization

9、(see text for details). Patients with serrated polyposis require close endoscopic follow- up with control of polyp burden by endoscopy or by surgical resection if the number, size or location of serrated polyps precludes endoscopic resection or if a cancer is diagnosed. 9 First degree relatives of p

10、atients with SPS should undergo colonoscopy at age 40 or 10 years before the age at diagnosis of SPS. Colonoscopy should be at 5 year intervals or more often if polyps are found. 10 There are few longitudinal observational studies after removal of serrated lesions on which recommendations for postpo

11、lypectomy surveillance can be based. Recommendations are mostly based on features of serrated lesions for which there is evidence of an association with increased risk of cancer or advanced neoplasms, including: proximal colon location, large size, increasing number, and histologic features includin

12、g SSA/P histology . Am J Gastroenterol, 2012 ,107(9): 13151330. 序言(introduction) 锯齿状病变(serrated lesions)的真正发病率，尤其 是结肠近段，可能高于先前的报道；相当数量的 内镜医师漏掉了半数以上的锯齿状病变。 流行病学 尸解研究显示25-50%的白种成人有一 个及以上锯齿状病变。内镜检出率很低。锯齿状 病变最常见于乙状结肠和直肠，其分布依据组织 学类型变化，70-95%的锯齿状病变为HPs，左半 结肠为主；SSA/Ps占5-25%，右半结肠为主，TSA 少于SSA/Ps，左半结肠常见。 对SSA

13、/P的认识时间相对较短，其诊断对低 年资病理医生常有困难； SSA/P诊断频率文献报道也是变化甚大。 MVHP与SSA/P交界性病变依然是一个诊断 问题。 近年来对SSA/P的诊断阈值趋向降低，认为 在MVHP背景中即使是有1个确定的结构扭 曲、扩张和/或水平分支的SSA/P样隐窝，也 可以诊断SSA/P(Am J Gastroenterol.2012, 107(9): 13151330)。 compartmentalization aberration,CCA (Am J Surg Pathol, 2014;38:158166) A HP pSSA type 1-3(B-D) 传统型锯齿状腺

14、瘤(TSA)伴异型增生 两种形态的异型增生：锯齿状异型增生和经 典腺瘤性异型增生(serrated dysplasia and conventional adenomatous dysplasia) 分类：TSA with serrated dysplasia,TSA with conventional adenomatous dysplasia and tubullovillous adenoma with serrated dysplasia, 后一种类型含少量serrated dysplasia 形态和分子病理学特征： TSA with serrated dysplasia-息肉小、与

15、BRAF突变高度相关；TSA with convetional adenomatous dysplasia and tubullovillous adenoma with serrated dysplasia，息肉较大 ，更多KRAS突变，后二者具有-catenin表 达，而前者无表达；但是，CpG岛甲基化和 BRAF突变很少见于经典腺瘤。 (Modern Pathology, advance online publication, 7 March 2014) Am J Gastroenterol, 2012 ; 107(9): 13151330. 不同的锯齿状病变隐窝与粘膜肌的关系模式图 H

16、P 增生性息肉增生性息肉 SSA/P HPsMVHP(left) Hyperplastic polyp MVHP GCHP MPHP borderline sessile serrated lesion A.介于介于HP和和SSA/P之间，仅有隐窝之间，仅有隐窝 扩张；扩张；B.SSA/P Mucosal prolapse polyps. SSA/P Examples of study MVHP (A) and pSSAs types 1 to 3 (BD) Am J Surg Pathol 2014;38:158166 SSA/P SSA/PSSA/P SSA/P 隐窝扩张和隐窝基底锯齿状 SSA/P Sessile serrated adenoma Sessile serrated adenoma of appendix Ki67显示隐窝增生区不对称 SSA/P with cytological dysplasia SSA/P with cytological dysplasia Mixed polyp TSA TSA TSA TSA TSA,低倍图像，显