内镜黏膜下剥离术治疗早期结直肠癌及癌前病变的非整块切除影响因素分析

目的 探讨内镜黏膜下剥离术(endoscopic submucosal dissection, ESD)治疗结直肠肿瘤发生非整块切除的影响因素。方法 回顾性收集2011年1月～2022年12月结直肠ESD临床病理资料,经病理证实为腺瘤、锯齿状病变、早期结肠癌共1251例患者1312个病变,比较整块切除组与非整块切除组的临床病理特征,采用单因素及多因素logistic回归分析ESD非整块切除的影响因素。结果 1312个病变长径(25.8±16.3)mm。腺瘤728个(55.5%),锯齿状病变193个(14.7%),腺癌391个(29.8%)。1306个病变完成ESD治疗,因穿孔或操作困难中止切除6个。病变整块切除率89.5%(1174/1312),完全切除率73.8%(968/1312),治愈性切除率70.6%(926/1312)。多因素logistic分析显示,病变长径≥40 mm(OR=6.329,95%CI:4.278～9.384,P<0.001)、抬举征阴性(OR=2.384,95%CI:1.424～3.903,P=0.005)、瘢痕部位病变(OR=2.997,95%CI:...     

左半结直肠癌根治术后锯齿状腺瘤的发生率及危险因素分析

目的:探讨左半结直肠癌根治术后锯齿状腺瘤(SSA)的发生率及危险因素。方法:回顾性分析2011 年9 月—2016 年9 月我院收治的270 例左半结肠癌和直肠癌手术患者为研究对象，术后进行了至少2 次结肠镜随访。收集患者基线特征、SSA 病理资料及结肠镜检查结果。结果:第1 次结肠镜检查平均随访时间为11.5 个月，第2 次平均随访时间为25.8 个月。在第1 次随访时，59 例患者(21.8%)发现了48 枚SSA。在第2 次随访中，63 例患者(23.3%)发现了40 枚SSA。88 枚SSA 在内窥镜检查中，49 枚(55.68%，49/88)表现为扁平状、31 枚(35.23%，31/88)表现为半球形隆起、8 枚(9.09%，9/88)表现为亚蒂。直径介于2.8~40.0 mm，其中，最大径＜ 5 mm 者61 枚(69.32%)，5~10 mm 者19 枚(21.59%)，>10 mm 者8 枚(9.09%)。多因素分析显示，体质量指数大、饮酒、TNM 分期高及分化程度低是影响患者术后首次结肠镜检查时并发SSA 的独立危险因素。结论:左半结直肠癌根治术后无蒂锯齿状腺瘤的发生率较高，特别是肥胖、饮酒、TNMⅢ期、肿瘤低分化患者更易并发SSA。     

结直肠无蒂锯齿状病变研究进展

<正>结直肠的锯齿状病变是结直肠癌锯齿状通路中的早期前驱病变，包括所有在隐窝上皮呈锯齿状形态的非恶性上皮肿瘤性病变。1996 年，Torlakovic等^[1]首先描述了无蒂锯齿状腺瘤，且指出这些病变的特点为表现出结构异常但没有细胞学发育不良。2019年 WHO 分类(第5版)中将锯齿状结直肠病变的术语和分类的变化进行了总结，     

71例结直肠锯齿状腺瘤内镜与病理学特征

目的 探讨结直肠锯齿状腺瘤（SA）的内镜下形态和病理组织学特征。方法 回顾性分析2002年1月至2005年7月南方医院消化内镜中心检出的71枚SA的内镜和病理资料。结果 71枚SA中47枚为隆起型（无蒂23枚，亚蒂5枚，有蒂19枚），24枚为表面型（扁平16枚，侧向发育型8枚），平均大小分别为10．5mm和16．6mm，常见于直肠及乙状结肠。组织病理学上，管状、管状绒毛状和绒毛状SA分别为53、9和9枚；不典型增生程度。轻度47枚，中度22枚。2枚局部有癌变病灶。10mm以下的SA不典型增生程度较大于或等于10mm SA轻（P〈0．01）。腺管开口（pit）分型的60枚SA中，Ⅳ型SA多由绒毛状腺体（64％）组成，ⅢL型SA多由管状腺体（68％）组成，但有40％的SA（24枚）表现为增生性息肉样的Ⅱ型，全部由管状腺体组成；腺体异型性Ⅱ型与ⅢL型相近而小于Ⅳ型息肉（P〈0．05）。结论 Ⅱ型pit的息肉可能为SA。SA具有肿瘤性息肉的一般特点，应视为一种新的可能性癌前病变。     

湖南省局部地区无症状结直肠腺瘤型息肉的流行病学特征分析

背景与目的:腺瘤型息肉是结直肠癌的主要癌前病变,早期发现腺瘤型息肉对预防结直肠癌具有重要的意义。本研究分析湖南省长沙、湘潭两地无症状体检人群结直肠腺瘤型息肉的检出率及分布特点,以期发现易感因素,从而进行早期筛查和预防。方法:回顾性分析2016年1月—2020年12月在中南大学湘雅医院及湖南省湘潭市中心医院健康体检中心行肠镜检查,且检出结直肠息肉的无症状体检者资料,通过病例对照研究比较腺瘤型与非腺瘤型息肉间流行病学指标的差异。结果:9235名无症状体检者中检出结直肠息肉1584例(17.15%),其中腺瘤型息肉881例。腺瘤型息肉患者中男性708例,女性173例,与非腺瘤型息肉性别构成差异无统计学意义(P=0.486);45~<60岁为腺瘤型息肉最常见的年龄段,与非腺瘤型息肉年龄构成差异有统计学意义(P=0.033);腺瘤型息肉检出者中,405例(45.9%)超重、353例非肥胖(40.1%)、123例肥胖(14.0%),与非腺瘤型息肉之间差异无统计学意义(P=0.859)。乙状结肠(37.5%)是结直肠腺瘤型息肉最常见的部位,而非腺瘤型息肉多见于直肠,差异有统计学意义(P=0.009)。结论:结直肠腺瘤型息肉好发于乙状结肠,发病与性别和肥胖程度无关,而与年龄有关,建议45岁以上人群定期进行肠镜筛查。     

结直肠无蒂锯齿状病变的特征和临床问题

无蒂锯齿状息肉/腺瘤（SSL）曾经被认为是良性病变,而现有研究表明,通过锯齿状瘤变途径,约15%～30%的SSL最终发展为结直肠癌。锯齿状息肉分为增生性息肉、无蒂锯齿状病变、伴发育不良的无蒂锯齿性病变、传统锯齿状腺瘤和未分类锯齿状腺瘤,每一种都具有不同的形态学和分子特征。尽管对SSL的理解有所提高,但由于频繁的病理错误分类、结肠内镜检测不足和不完全切除率高,SSL仍然是内镜和病理医生面临的诸多临床挑战。本文总结了目前对锯齿状息肉的新认识和诊断问题。     

内镜下结直肠锯齿状病变的临床特征

结直肠癌在我国其发病率和病死率呈逐年上升趋势,故对结直肠癌前病变的早期诊断具有重要临床意义。结直肠锯齿状病变是近年来才被证实的一类新的结直肠癌前病变。2010年,WHO消化系统肿瘤分类对锯齿状病变做了明确定义,并对分类及诊断标准做了详细介绍［1］。将其定义为一组以上皮锯齿状结构为特征的病变,包括增生性息肉（HP）、无蒂锯齿状腺瘤（息肉）（SSA／P）及传统锯齿状腺瘤（TSA）;并在结直肠癌亚型中分出锯齿状腺癌（serrated adenocarcinoma,SAC）。一般认为,HP为良性病变,SSA／P和TSA是锯齿状癌前病变,可通过锯齿状分子遗传学及表观遗传学途径发生癌变,最终发展为锯齿状腺癌。     

结直肠息肉的癌变因素分析及治疗方法探讨

目的：探讨结直肠息肉癌变的相关因素和治疗方法。方法：回顾分析电子结肠镜检查出的结直肠息肉患的临床、内镜及病理资料，分析影响结直肠息肉病变的相关因素。结果：124例结直肠息肉中，以左半结肠、圆形、单个、腺瘤性息肉居多。息肉癌变或同时伴有肠癌的20例中，有19例是腺癌性息肉。多发性息肉癌变率（39．5％）高于单个或2个息肉患。直径2．0cm以上息肉癌变率（29．4％）高于2．0cm以下的患。肠镜下息肉除99例，肠发开息肉切除4例，肠切除术21例。结论：结直肠息肉数目越多越大癌变率越高，多发广基腺瘤性大息肉最易癌变。带蒂的息肉和小而无蒂的息肉，均可在结肠镜下除。伴肠癌息肉、有癌变的较大息肉或多发性息肉则应当行肠切除术。     

内镜下尼龙绳套扎联合高频电凝切除治疗结直肠息肉的疗效

目的 探讨内镜下应用尼龙绳套扎联合高频电凝切除治疗结直肠息肉的临床疗效与安全性.方法 回顾性分析2006年1月至2011年1月复旦大学附属中山医院内镜下应用尼龙绳套扎联合高频电凝切除治疗345例结直肠息肉患者的临床资料.观察患者术后有无出血、穿孔等并发症发生;肠镜随访观察患者术后创面愈合及病变残留、复发情况.结果 345例患者共成功切除362枚结直肠息肉.息肉直径1.5 ～4.0 cm,平均直径2.7 cm;1例患者术中出血;1例患者发生迟发性穿孔.93.6％(339/362)的息肉经病理检查证实为腺瘤性息肉,17枚为增生性息肉,5枚为炎症性息肉,1枚息肉出现癌变.334例患者术后1个月复查肠镜,9例患者残蒂存留,再次予内镜下切除,其余患者术后创面愈合良好,残蒂脱落消失.308例患者术后2个月获得肠镜检查随访,病灶均完全消失.患者首次治疗有效率为97.1％( 299/308).结论 内镜下应用尼龙绳套扎联合高频电凝切除结直肠息肉安全、有效.     

结直肠腺瘤性息肉与幽门螺杆菌感染和血脂水平的相关性

目的:研究结直肠腺瘤性息肉与幽门螺杆菌感染和血清胃泌素水平的相关性。方法:选取2017年9月—2018年6月在惠州市第三人民医院接受胃肠镜检查患者200例,并按照检查结果分为观察组(结直肠腺瘤性息肉)和对照组(结肠无明显异常)各100例。所有研究对象均接受碳14尿素呼气试验检查和血脂检查,根据检测结果统计观察组息肉数目、大小、部位与幽门螺杆菌感染情况,息肉山田分型、病理分型与幽门螺杆菌感染情况,并比较不同息肉数目、大小、部位患者的血脂水平及两组幽门螺杆菌感染阳性和阴性患者血脂水平。结果:观察组幽门螺杆菌感染阳性率61.0%,高于对照组的42.0%,差异有统计学意义(P0.05);观察组中,多发性、大息肉(≥10 mm)和左半结肠息肉的幽门螺旋杆菌阳性率明显高于单发性、小息肉(10 mm)和右半结肠,差异有统计学意义(P0.05);观察组中,山田分型、病理分型各分型之间幽门螺杆菌阳性率比较,差异无统计学意义(P0.05);左半结肠息肉患者的甘油三酯(TG)、总胆固醇(TC)及低密度脂蛋白胆固醇(LDL-C)水平与右半结肠息肉患者比较,差异均无统计学意义(P0.05);多发性、大息肉(≥10 mm)患者的TG、TC、LDL-C水平均分别高于单发性、小息肉患者,差异有统计学意义(P0.05);两组中幽门螺杆菌感染阳性患者的TG、TC、LDL-C水平均分别高于幽门螺杆菌感染阴性患者,差异有统计学意义(P0.05)。结论:幽门螺杆菌感染及血脂水平的异常均可促进结直肠腺瘤性息肉的发生与发展,对于幽门螺杆菌感染阳性者,临床上应积极采取有效的措施进行干预,以便预防和抑制结直肠腺癌性息肉发展成结直肠癌。     

Importance of serrated polyps in colorectal carcinogenesis

Colorectal cancer is an invasive neoplasm of the glandular epithelium of the colon and rectum that begins in a precursor lesion and expands to replace its lesion of origin. The majority of colorectal cancers arise from an adenoma, and the ‘adenoma to carcinoma’ pathway has been acknowledged for decades. More recently, another precursor lesion has been recognized: the serrated polyp. Serrated polyps are characterized by a sawtooth appearance of the crypt epithelium resulting from failure of apoptosis and a build‐up of aging colonocytes. Although initially felt to be innocent of involvement in colorectal carcinogenesis, some types of serrated polyp are being increasingly recognized as precursor lesions, prone to develop into cancer, and likely to be a cause of ‘missed’ or interval cancers after colonoscopic screening. It is essential that gastrointestinal specialists appreciate the clinical significance of these lesions and what that means for colorectal cancer screening, and prevention. The purpose of this review is to highlight the importance serrated lesions of the colon and rectum, and to summarize current opinion on their natural history, diagnosis, surveillance and treatment.     

Apoptosis index and apoptosis-related antigen expression in serrated adenoma of the colorectum: the saw-toothed structure may be related to inhibition of apoptosis.

Serrated adenoma of the colorectum is a recently proposed entity characterized by a saw-toothed structure of hyperplastic polyp and cytologic atypia of tubular adenoma. To clarify the role of apoptosis in morphogenesis of serrated adenoma, we investigated apoptotic indices and expression of apoptosis-related antigens in the tumor cells. Thirty-eight serrated adenomas were examined by the nick-end DNA labeling method and immunostained for CD95 (Fas), bcl-2, bax, and p53. Thirty-seven hyperplastic polyps, 48 tubular adenomas, and 16 sections containing normal colonic mucosa were similarly examined for comparison. The apoptotic indices in the upper and middle zones of the crypts of serrated adenomas and hyperplastic polyps were lower than those of normal colon mucosa and tubular adenomas with statistically significant differences. The CD95 expression was diffusely observed throughout the epithelium of normal crypts and tubular adenomas, whereas it was reduced in serrated adenomas and hyperplastic polyps. The bcl-2 expression was confined to the basal crypts in the latter two lesions but was diffuse throughout the neoplastic epithelium in tubular adenomas. The bax expression was increased in serrated adenomas and tubular adenomas but was decreased in hyperplastic polyps. Overexpression of p53 protein was observed in 50% of serrated adenomas, none of hyperplastic polyps, and 14% of tubular adenomas. These findings suggest that inhibition of apoptosis is caused by reduced CD95 expression in serrated adenomas and hyperplastic polyps, which may induce the characteristic saw-toothed structure in these lesions. Based on the similarities and differences between serrated adenoma and hyperplastic polyp observed in the present study, a progression from the latter to the former lesion may be postulated.     

Benign serrated colorectal fibroblastic polyps/intramucosal perineuriomas are true mixed epithelial-stromal polyps (hybrid hyperplastic polyp/mucosal perineurioma) with frequent BRAF mutations

Colorectal fibroblastic polyp and intramucosal perineurioma are 2 synonyms for a recently described benign mucosal lesion with a predilection for the rectosigmoid colon. These lesions are characterized by aggregates of bland spindled cells separating and distorting mucosal crypts. The latter frequently showed a serrated architecture. The pathogenesis of fibroblastic polyp/intramucosal perineurioma and the nature of serrated crypts observed in them are poorly understood. We analyzed the clinicopathological features of 29 fibroblastic polyps and investigated them for the first time for mutations known to be involved in serrated colorectal epithelial polyps (BRAF, KRAS, and PIK3CA). Patients were 23 women and 6 men with a mean age of 64 years (range: 47 to 84?y). All lesions represented asymptomatic solitary polyps (mean size 3.5?mm) localized predominantly in the rectosigmoid colon (81%). Hyperplastic polyps, classical adenoma, and sessile serrated adenoma/lesion coexisted in 12 (44%), 12 (44%), and 5 (17%) patients, respectively. All lesions showed irregular aggregates of bland spindled cells separating and distorting mucosal crypts. Serrated (hyperplastic) crypts were observed on the top or contiguous with the lesion in all cases. Immunohistochemistry revealed expression of at least one perineurial cell marker (epithelial membrane antigen, claudin-1, and glucose transporter-1) in 26 out of 27 lesions (96%), but expression of CD34 was less common (8 of 27; 30%). Immunostaining for hMLH1 showed a normal nuclear expression. Molecular analysis in 22 cases showed V600E BRAF mutation in 14 cases (63%) and KRAS mutation in 1 (4%). The remainder were wild-type for all 3 genes. Our results indicate that serrated fibroblastic polyps/intramucosal perineuriomas represent a unique type of mixed epithelial-stromal polyps (hybrid hyperplastic polyp/mucosal perineurioma). The perineurial stromal component might be derived from modified pericryptic fibroblasts as a consequence of a yet poorly understood epithelial-stromal interaction.     

Morphologic reappraisal of serrated colorectal polyps

The "hyperplastic polyp" is considered a benign lesion with no malignant potential, whereas "serrated adenoma" is a precursor of adenocarcinoma. The morphologic complexity of the serrated adenoma varies from being clearly adenomatous to being difficult to distinguish from hyperplastic polyp, which creates a need for more detailed morphologic analysis of all serrated polyps. We evaluated 24 morphologic variables in 289 serrated polyps from the colon and rectum. Cluster analysis and discriminant analysis were performed. A subset of polyps was immunostained for hMLH1 and hMSH2. Major differences were found between right-sided and left-sided polyps. A distinct group of serrated polyps with abnormal proliferation was identified throughout the colon and rectum. These polyps demonstrated decreased expression of hMHL1 and hMSH2 compared with polyps with normal proliferation. Left-sided serrated polyps with normal proliferation further clustered into three groups: vesicular cell-type, goblet cell-type, and mucin-poor-type. We recommend evaluation of the localization, size, and morphologic features when serrated polyps are included in colorectal carcinogenesis research. Polyps with abnormal proliferation are similar to the polyps in "hyperplastic polyposis" and, because of their decreased expression of hMLH1 and hMSH2, may be the subset of polyps associated with the development of colorectal carcinoma via the microsatellite instability pathway.     

Serrated Colorectal Neoplasia

Until very recently, there was general acceptance in the pathology community that all serrated lesions of the colon and rectum without overt cytologic dysplasia were hyperplastic polyps and had no malignant potential. Although there are still several unanswered questions in regard to the relationship between the various serrated lesions, there is a better understanding of the relationship of sessile serrated adenoma to carcinoma. This article discusses hyperplastic polyps, sessile serrated adenoma, traditional serrated adenoma, mixed polyps, and serrated lesions in such conditions as idiopathic inflammatory bowel disease and mechanical trauma. The major focus of the content is on diagnostic features of these lesions.     

Serrated polyps: new classifications highlight clinical importance

Aim Many lesions previously classified as hyperplastic polyps and therefore thought to be innocuous have been reclassified as sessile serrated adenomas/polyps (SSA/Ps), establishing their place in the serrated pathway and underscoring their malignant potential. The clinical relevance of this new nomenclature is incompletely defined. This study examines the incidence and characteristics of colorectal SSA/Ps and describes other associated colorectal neoplasia. Method A single institution pathology database was searched for the diagnosis of SSA/Ps between January 2004 and October 2007. SSA/Ps found by colonoscopy were included. Patient demographics, SSA/P characteristics and associated colonoscopic findings were retrospectively recorded. Results A total of 585 SSA/Ps were removed during 519 colonoscopies in 483 patients performed by 64 different endoscopists. This represented an overall incidence of SSA/Ps per colonoscopy of 2.1% in the 28 054 colonoscopies performed during the study period. The median SSA/P size was 0.8 cm (range 0.2–4.5) and 188 (69%) were ≥ 1.0 cm. Of the 585 SSA/Ps, 366 (63%) were right‐sided, 129 (22%) were in the left colon and 90 (15%) were in the rectum. Also, 439 synchronous polyps of other histology (mainly adenomas and hyperplastic polyps) were found during the same 519 colonoscopies. Conclusion SSA/Ps are rare lesions found during colonoscopy that may coexist with small hyperplastic polyps. Because SSA/Ps are part of the serrated oncogenic pathway, all, even those appearing to be hyperplastic, should be removed or biopsied for diagnosis. Careful review of historical lesions with application of new definitions may redefine risk for malignancy.     

Minimally invasive treatment of synchronous colorectal tumours

In patients with colorectal cancers synchronous neoplastic lesions are an increasingly frequent finding at preoperative staging; 3% of the cases are other cancers while 33-35% of the synchronous lesions are villous adenomas. The treatment of most colorectal adenomas can be performed by endoscopic poplypectomy. In 5% of cases there are synchronous colorectal lesions also requiring surgical treatment. From January 1995 to June 2007 we treated 5 patients with rectal lesions by transanal endoscopic microsurgery (TEM) together with a laparoscopic colectomy for the presence of synchronous lesions at the "Clinica Chirurgica Generale e d'Urgenza" of the University of Perugia,. Surgical timing involved performing a sequential exeresis characterised by a cancer resection, followed by resection of the voluminous adenoma: TEM for rectal cancer followed by a laparoscopic right hemicolectomy with an extracorporeal anastomosis for a voluminous villous adenoma (1 patient) and laparoscopic right hemicolectomy with an extracorporeal anastomosis for cancer followed by TEM for a voluminous villous adenoma (2 patients). One patient with left colon cancer associated with a voluminous villous rectal adenoma first underwent TEM for the rectal adenoma and then a left laparoscopic hemicolectomy with an extracorporeal anastomosis in order to ease the transit of the circular mechanical stapler. Another patient with rectal and right colon adenomas first underwent TEM for a voluminous rectal sessile adenoma and later a right hemicolectomy. The use of this minimally invasive approach allowed rectum preservation and less invasive surgery.     

Snaring large serrated polyps

Background

Serrated polyps of the large bowel are potentially premalignant, difficult to see, but important to remove. Few studies describe the technique or outcomes of serrated polypectomy. We sought to present outcomes of a series of polypectomies of large serrated polyps in comparison to a series of endoscopic resections of large adenomas.

Methods

This retrospective, comparative, single endoscopist study was performed in an outpatient colonoscopy department of a tertiary referral medical center. Patients had outpatient colonoscopy where a large (≥2 cm) serrated polyp or adenoma was removed. Outcomes were completeness of excision and complications of polypectomy. A database of endoscopic polypectomies was reviewed. Polypectomy of large serrated polyps was compared with polypectomy of large adenomas.

Results

There were 132 large serrated polyps in 112 patients and 563 adenomas in 428 patients. More serrated polyps were right sided (120 of 130, 92.3 %, vs. 379 of 563, 67 %) (p < 0.0001). The serrated polyps were smaller than the adenomas (mean 25.5 ± 7.9 mm standard deviation) versus 36.8 ± 16.9 mm standard deviation (p < 0.001). There were four complications of serrated polypectomy in four patients (4 % of polyps, 5 % of patients): three postpolypectomy bleeds and one postpolypectomy syndrome. There were 33 complications of adenoma removal (31 postpolypectomy bleeding and two postpolypectomy syndrome) (6.9 % of polyps, p = 0.376, 8.4 % of patients, p = 0.371). On follow-up, 36 of 51 patients (71 %) with serrated polyps had metachronous lesions compared to 133 of 298 patients (45 %) with adenomas (p < 0.0001). There were fewer residual polyps in the serrated group (4 of 47 vs. 64 of 298, p = 0.001).

Conclusions

Removal of large serrated colorectal polyps is no more complicated than polypectomy of similarly sized adenomas. However, large serrated polyps have a higher rate of metachronous polyps than similarly sized adenomas and surveillance should be adapted to reflect these findings.     

Phenotype and polyp landscape in serrated polyposis syndrome: a series of 100 patients from genetics clinics

Serrated polyposis syndrome (SPS), also known as hyperplastic polyposis, is a syndrome of unknown genetic basis defined by the occurrence of multiple serrated polyps in the large intestine and associated with an increased risk of colorectal cancer (CRC). There are a variety of SPS presentations, which may encompass a continuum of phenotypes modified by environmental and genetic factors. To explore the phenotype of SPS, we recorded the histologic and molecular characteristics of multiple colorectal polyps in patients with SPS recruited between 2000 and 2010 from genetics clinics in Australia, New Zealand, Canada, and the United States. Three specialist gastrointestinal pathologists reviewed the polyps, which they classified into conventional adenomas or serrated polyps, with various subtypes, according to the current World Health Organization criteria. Mutations in BRAF and KRAS and mismatch repair protein expression were determined in a subset of polyps. A total of 100 patients were selected for the study, of whom 58 were female and 42 were male. The total polyp count per patient ranged from 6 to 150 (median 30). The vast majority of patients (89%) had polyposis affecting the entire large intestine. From this cohort, 406 polyps were reviewed. Most of the polyps (83%) were serrated polyps: microvesicular hyperplastic polyps (HP) (n=156), goblet cell HP (n=25), sessile serrated adenoma/polyps (SSA/P) (n=110), SSA/P with cytologic dysplasia (n=28), and traditional serrated adenomas (n=18). A further 69 polyps were conventional adenomas. BRAF mutation was mainly detected in SSA/P with dysplasia (95%), SSA/P (85%), microvesicular HP (76%), and traditional serrated adenoma (54%), whereas KRAS mutation was present mainly in goblet cell HP (50%) and in tubulovillous adenoma (45%). Four of 6 SSA/Ps with high-grade dysplasia showed loss of MLH1/PMS2 expression. CRC was diagnosed in 39 patients who were more often found to have a conventional adenoma compared with patients without CRC (P=0.003). Patients with SPS referred to genetics clinics had a pancolonic disease with a high polyp burden and a high rate of BRAF mutation. The occurrence of CRC was associated with the presence of conventional adenoma.