Total colonic polyp diameter: a marker for the risk of malignancy?

BACKGROUND/AIMS: The correlation of the risk of malignancy with the sum of the diameters of small colonic polyps is unknown, and data regarding this topic are lacking. In this study, the relationship between the sum of the diameters of the total number of colonic polyps and poor histopathologic characteristics was examined. METHODS: A total of 920 neoplastic colon polyps were evaluated in 480 patients. The "total polyp diameter" (i.e. the sum of all polyp diameters identified during colonoscopy), which was calculated in each patient by adding the diameter of each polyp to a sum, was categorized as "small" (<10mm in diameter) or "large" (> or =10mm in diameter). The polyps were further categorized by histopathologic component as "unfavorable" or "favorable" and were divided into 2 groups: group 1 (those identified as carci noma, carcinoma in situ, villous adenoma, and tubulovillous adenoma with a villous component of more than 25%) and group 2 (mixed adenomatous polyps with various degrees of hyperplastic or inflammatory components and adenomas with a tubular component of more than 75%). RESULTS: Large polyps that had a total diameter greater than or equal to 10mm tended to have poor histopathologic characteristics (p<0.05). Polyps generally tended to localize in the left portion of the colon, and malignant polyps or those at risk for malignancy in particular tended to localize in the left colon (p<0.05). CONCLUSIONS: Polypectomy is recommended for patients in whom the sum of the diameter of all colonic polyps exceeds 10mm.     

不同结肠息肉内窥镜资料和癌变率的回顾性对比分析

本文回顾分析了本院1986年1月至1996年6月经活检、电切及手术病理证实的426例结肠息肉病人,共583枚息肉。结果显示:最常见的为炎性息肉、其次为管状腺瘤;息肉好发部位为直肠和乙状结肠。息肉好发年龄在50—69岁,肿瘤性息肉的平均年龄较肿瘤样息肉明显为高,而腺瘤癌变者平均年龄更高;各种肿瘤性息肉和幼年性息肉的直径均较炎性息肉和血吸虫卵性息肉等为大,而腺瘤癌变者直径更大;本组病例中发生癌变者均为腺瘤性息肉,占腺瘤病人的3.99%,其中管状腺瘤、乳头状腺瘤、混合性腺瘤癌变率分别为1.72%、30%、25%,女性乳头状腺瘤癌变率则高达44.44%。这提示对于年龄较大,息肉直径较大,腺瘤样息肉,尤其是乳头状腺瘤及混合性肿瘤应高度警惕其癌变可能,对女性乳头状腺瘤更要特别注意。     

代谢综合征对结直肠管状绒毛状腺瘤的影响因素分析

目的分析结直肠管状绒毛状腺瘤与代谢综合征的关系。 方法收集2017年6月至2020年12月南方医科大学附属惠阳医院经手术病理确诊的271例患者。其中管状腺瘤患者203例，管状绒毛状腺瘤患者68例。比较结直肠管状腺瘤与管状绒毛状腺瘤患者纤维结肠内镜检查的基本情况，结直肠息肉一般特征、数目、病理，以及代谢综合征相关指标水平等。采用Logistic多因素回归分析山田分型、最大息肉直径、代谢综合征相关指标与结直肠管状绒毛状腺瘤的关系。 结果累计息肉数目最多部位、最大息肉好发部位、病理为管状绒毛状腺瘤/管状腺瘤好发部位均为乙状结肠。结直肠管状腺瘤与管状绒毛状腺瘤患者山田分型、最大息肉直径、血清甘油三酯水平差异均有统计学意义（P均<0.01），而高血压、脂肪肝、空腹血糖受损或糖尿病情况及总胆固醇水平、血清尿酸水平、癌胚抗原水平差异均无统计学意义（P>0.05）。Logistic多因素回归分析结果显示，山田分型及最大息肉直径与结直肠管状绒毛状腺瘤有关联[Wald χ²=5.756，Exp（B）=2.494，P=0.016；Wald χ²=23.173，Exp（B）=12.842，P<0.001]，而血清甘油三酯水平与结直肠管状绒毛状腺瘤无关联。 结论与结直肠管状腺瘤患者相比，代谢综合征与结直肠管状绒毛状腺瘤发病并无直接关联，但息肉直径大小及山田分型与结直肠管状绒毛状腺瘤发病有关联。     

老年人与中青年人大肠息肉临床特点对比研究

目的 探索老年人大肠息肉的临床特征.方法 收集在上海中医药大学附属曙光医院2006年1月-2019年12月行电子结肠镜检查并且病理证实为大肠息肉的患者1 000例,进行回顾性研究,按年龄分为老年组576例,中青年组424例.统计分析老年大肠息肉患者的临床症状、息肉大小、形态、部位、数目、息肉病理分型及其与息肉癌变的相关...     

Immunocytochemical Localization of Lymphatic and Venous Vessels in Colonic Polyps and Adenomas

Histopathological localization of lymphatic vessels has been hindered because of a lack of suitable immunocytochemical markers for lymphatic vessels. Using lymphatic vessels endothelial hyaluronan receptor-1 (LYVE-1) immunocytochemical staining, hyperplastic polyps, tubular adenomas to villous adenomas, were investigated for lymphatic vessels compared with immunostained blood vessels using factor-8. Four cases each of hyperplastic polyps, tubular adenomas to villous adenomas, were routinely fixed in formalin and embedded in paraffin and were immunostained using goat anti-LYVE-1 for lymphatic vessels and rabbit anti-factor-8 for blood vessels. In normal colon and hyperplastic polyps, slender lymphatic vessels were noted in muscularis mucosa, which spread into the base of colonic crypt, whereas round venous vessels, they extend into lamina propria. In tubular adenomas, small lymphatic and venous vessels were noted in broad fibrous stalks. In villous adenomas, smaller lymphatic and venous vessels were noted in fine intervillous stroma. In normal colon and hyperplastic polyps, slender, irregularly shaped lymphatic vessels were present in muscularis mucosa, spreading into the base of the colonic crypt. In tubular adenomas, small lymphatic and venous vessels were noted in fibrous stalks. In villous adenomas, smaller lymphatic and venous vessels were noted in intervillous stroma. There are no increased lymphatic and venous vessels in intermucosal stroma and stalks of adenomas compared with normal colon.     

Accuracy of pathologic interpretation of colorectal polyps by general pathologists in community practice.

BACKGROUND: The histologic features of colorectal polyps often guide colonoscopic surveillance and the need for surgical intervention. Our objective was to evaluate the pathologic interpretation of colorectal polyps by general pathologists in community practice. METHODS: Twenty histologic slides of colorectal polyps were reviewed by 20 randomly selected general pathologists in community practice. There were 5 malignant polyps, 9 adenomas, and 6 miscellaneous polyps. RESULTS: Cancer was correctly identified in 91% of readings and adenoma in 94%. The grade of differentiation of cancer was provided in 55% of readings, and comment regarding whether the resection margin was free of cancer was made by 50% of pathologists. Tubular adenoma was called tubulovillous or villous in 35% of readings, but tubulovillous or villous adenoma was seldom (2%) called tubular. High-grade dysplasia was correctly identified in 47% of 60 readings, was called invasive cancer in 22%, and was missed in 31%. Among miscellaneous polyps, hyperplastic polyp was correctly recognized in 75% of cases, and inflammatory polyp and juvenile polyp each were recognized by 16 of 20 pathologists (80%). Peutz-Jeghers hamartoma was identified by 4 of 20 pathologists (20%), and the polypoid phase of solitary rectal ulcer syndrome was recognized by 2 pathologists (10%). CONCLUSION: Areas of strength with regard to interpretation of colon polyps by general pathologists in community practice included identification of cancer, adenoma, and certain non-neoplastic polyps (e.g., inflammatory and juvenile polyps). Areas of weakness included lack of comment on cancer differentiation and proximity to the resection line, erroneous identification of high-grade dysplasia, and identification of rare lesions. The results of this study suggest areas on which to focus continuing education and continuous quality improvement efforts with regard to polyp interpretation.     

Phenotypic markers for a spectrum of colonic polyps and cancers

The purpose of this study was to determine if a panel of monoclonal antibodies could define phenotypic markers that could be used in risk assessment of a spectrum of colonic polypes and colon cancers. Using the ABC immunoperoxidase technique on formalin-fixed sections of surgical specimens, the following results were obtained: 1) Mab B72.3 demonstrated increased reactivity in villous lesions and cancers compared with hyperplastic polyps and tubular adenomas; 2) Mab anti-CAA demonstrated increased reactivity in polyps compared with colon cancers; and 3) using the two antibodies (Mab B72.3 and Mab anti-CAA), a malignancy ratio was obtained that determined malignancy risk for individual polyps. No hyperplastic polyp gave a positive ratio, but about 30 percent of villous lesions were positive. Over 50 percent of villous lesions greater than 2 cm in size had a positive ratio. The malignancy potential ratio may be a valuable marker in assessing risk of malignancy in an individual case.     

Hyperplastic polyps and the risk of adenoma recurrence in the polyp prevention trial

BACKGROUND AND AIMS: Recent studies have suggested that some hyperplastic polyps may be associated with an increased risk of colorectal cancer. Prospective information on the risk of adenoma recurrence associated with hyperplastic polyps is limited. We sought to investigate whether the coexistence of hyperplastic polyps with adenomas increases the risk of adenoma recurrence. METHODS: We used unconditional logistic regression models to examine the association between baseline hyperplastic polyps and subsequent adenoma recurrence during a 3-year follow-up evaluation, among 1637 participants in the Polyp Prevention Trial. RESULTS: A total of 437 participants (26.7%) had hyperplastic polyps coexisting with adenomas at baseline. Of these, 132 (30.2%) had at least one hyperplastic polyp in the proximal colon, whereas 305 (69.8%) had only distal hyperplastic polyps. When compared with subjects without any hyperplastic polyps at baseline, there was no statistically significant association between the presence of baseline hyperplastic polyps and recurrence of any adenoma (odds ratio [OR], 1.19; 95% confidence interval [CI], 0.94-1.51) or advanced adenoma (OR, 1.25; 95% CI, 0.78-2.03). Also, there was no association between hyperplastic polyp location and adenoma recurrence (OR, 1.01; 95% CI, 0.69-1.48) for any proximal hyperplastic polyp (OR, 1.26; 95% CI, 0.96-1.65) and for distal hyperplastic polyps. CONCLUSIONS: The coexistence of hyperplastic polyps with adenomas, irrespective of location, does not confer an increased risk of adenoma recurrence beyond that of adenomas alone within 3 years of follow-up evaluation. Prospective long-term studies on adenoma recurrence risk associated with hyperplastic polyps in screening populations are needed.     

Hyperplastic polyposis associated with two asynchronous colon cancers

We report a patient with hyperplastic polyposis who had two asynchronous colon cancers, a combined adenoma-hyperplastic polyp, a serrated adenoma, and tubular adenomas. Hyperplastic polyposis is thought to be a precancerous lesion; and adenocarcinoma arises from hyperplastic polyposis through the hyperplastic polyp-adenoma-carcinoma sequence. Most polyps in patients with hyperplastic polyposis present as bland- looking hyperplastic polyps, which are regarded as non- neoplastic lesions; however, the risk of malignancy should not be underestimated. In patients with multiple hyperplastic polyps, hyperplastic polyposis should be identified and followed up carefully in order to detect malignant transformation in the early stage.     

Small colorectal polyps

The histology of small (≤0.5 cm.) colorectal polyps removed during total colonoscopy in 303 patients was reviewed to determine their clinical significance. There were 178 male patients and 125 females, with a median age of 64 years (range, 26 to 97 years). A total of 766 polyps were treated, 60 percent being adenomatous and 22 percent hyperplastic. Hyperplastic polyps were more common in the rectum (71 percent) while adenomas were more common in the colon (63 percent). Hyperplastic polyps in the colon were associated with adenomas in 75 percent of cases and hyperplastic rectal polyps were associated with proximal adenomas in 63 percent. There were six mixed hyperplastic/adenomatous polyps. Of the 458 adenomas, 449 were tubular, eight were tubulovillous, and one was villous. Moderate dysplasia was noted in 23 (5 percent) and severe dysplasia in four (0.9 percent). There were associated large adenomas in 84 patients. Small colonic polyps are usually adenomatous and should be destroyed. Biopsy may be important if no other neoplasm has been identified. Small rectal polyps are usually hyperplastic but may be associated with proximal adenomas. Because of the uncertain significance of hyperplastic polyps they should also be treated, and are a relative indication for total colonoscopy. Read at the meeting of the American Society of Colon and Rectal Surgeons, Washington, D.C., April 5 to 10, 1987.     

Predictors of presence, multiplicity, size and dysplasia of colorectal adenomas. A necropsy study in New Zealand.

Three hundred and thirty six forensic necropsy specimens of large bowel were examined in order to identify subject related variables that independently predicted the following adenoma characteristics: presence, size (largest), multiplicity and high grade dysplasia. The variables were age, gender, body mass index, race (European origin versus Maori/Polynesian) and presence of hyperplastic (metaplastic) polyp(s). Subjects included 303 New Zealanders of European origin (M = 185, F = 118) yielding 149 adenomas and 251 hyperplastic polyps and 33 Maori/Polynesians (M = 25, F = 8) yielding five adenomas and one hyperplastic polyp. Independent predictors of adenoma presence as determined by regression analysis were age (p = 0.0001), presence of hyperplastic polyps (p = 0.0001) and male gender (p = 0.05). Models were poor at explaining variation in size, multiplicity, and dysplasia. Larger adenomas occurred more frequently in subjects with multiple adenomas (p = 0.03) and multiple adenomas were probably associated with hyperplastic polyps (p = 0.09) and male gender (p = 0.09) in Europeans. High grade dysplasia was more frequent in women (p = 0.05) and possibly in subjects with hyperplastic polyps (p = 0.2). Body mass index and ethnicity did not predict any adenoma characteristics, but hyperplastic polyp prevalence was influenced by European origin (p = 0.04) and to a lesser extent by body mass index (p = 0.08) as well as presence of adenoma (p = 0.0002) and age ( = 0.005). The association of hyperplastic polyp with presence, multiplicity but not size of adenoma and with a high risk group for colorectal cancer (New Zealanders of European origin) suggests that the hyperplastic polyp serves as a marker for a factor which influences neoplastic evolution at the stages of initiation/transformation but not promotion. Fifty nine per cent of individuals with adenoma(s) did not have hyperplastic polyp(s) emphasising that the last would serve only as a marker of populations and not individuals at high risk of bowel cancer. Low intracolonic butyrate may be the factor linking the expression of the two types of polyp.     

Histologic characteristics of gastric polyps in Korea： Emphasis on discrepancy between endoscopic forceps biopsy and endoscopic mucosal resection specimen

AIM: To investigate histological characteristics of gastric polyps in the Korean population. METHODS: We reviewed endoscopic photographs and medical records of patients with gastric polyps who underwent endoscopic mucosal resection from April 1996 through February 2003. RESULTS: A total of 85 gastric polyps from 74 patients were reviewed. Male-to-female ratio was 1:1.96. Mean age was 59.9±10.8 years. Multiple polyps were observed in 10.8%. Gastric polyps occurred most frequently in the antrum (58.8%). Pathological results on resected specimens were as follows: tubular adenoma 45.9%, hyperplastic polyp 31.8%, inflammatory polyp 9.4%, hamartoma 3.5%, fundic gland polyp 2.4%, tubulovillous adenoma 2.4%, adenocarcinoma 2.4%, dysplasia 1.1%, and mucosal pseudolipomatosis 1.1%. Discrepancy rate between endoscopic biopsy and pathology of resected specimens was 27.1%. There was no relationship between the size of the polyp and concordance rate. CONCLUSION: There is considerable discrepancy in histologic findings between endoscopic forceps biopsy and resected specimens. Approaches to review of the histology of an entire polyp should be performed, especially when an adenoma is suspected.     

Prevalence and Malignant Potential of Colorectal Polyps in Asymptomatic, Average-Risk Men

Screening colonoscopy was performed on 119 asymptomatic elderly men with no other risk factors for colonic neoplasms. Ninety adenomas were detected in 49 (41%) subjects. Mean adenoma size was 6.5 mm, with 83 (92%) less than or equal to 10 mm. Forty-nine (54%) adenomas were located proximal to the splenic flexure, and 17 (19%) were classified as tubulovillous or villous. Moderate- to high-grade dysplasia was found in 29 (32%) adenomas and was associated with larger size (p less than 0.0001) and villous architecture (p = 0.0038). Two subjects harbored adenomas with invasive cancer. Seventy-one hyperplastic polyps were found in 40 (34%) subjects. The mean size of hyperplastic polyps was 3.4 mm, and 64 (90%) were located in the left colon. We conclude that, in this population, adenomas are common lesions that are frequently small. However, substantial proportions of these adenomas may be at risk for malignant degeneration due to the presence of villous architecture and higher grades of dysplasia. Because adenomas and hyperplastic polyps are endoscopically indistinguishable, all polyps found at endoscopy should be removed or ablated.     

大肠息肉与大肠癌的演变关系（附494例分析）

本组息肉患者４９４例，癌变者１０１例，随着息肉的增大，其癌变率也增加。恶变息肉主要分布在直肠（５７．４％），次为乙状结肠（１９．８％）。管状腺瘤瘤体较小，恶变率较低，绒毛型腺瘤瘤体较大，恶变率较高，且呈重度不典型增生多见。单发息肉癌变率１３．１％，２－５个息肉者癌变率２４．４％，６个以上者癌变率３８．０％，腺瘤病１２例全部癌变。息肉癌变时间１至１５年。癌变术后标本病理均见癌旁组织残存良性管状腺瘤或绒毛型腺瘤成份，从组织学上证明了息肉癌变过程。     

大肠侧向发育型肿瘤内镜下的诊断与治疗

目的探讨大肠侧向发育型肿瘤（LST）临床病理特征及内镜下黏膜切除术的有效性、安全性。方法经普通内镜检查发现LST 119例,染色后观察病灶大小及部位并进行形态分型,再结合放大内镜确定腺管开口类型。有治疗适应证者行内镜下黏膜切除术,切除病灶黏膜送病理检查。结果 28个月中共发现119例LST 124个病变。内镜下分型：颗粒均一型44个,结节混合型48个,平坦隆起型23个,假凹陷型9个。病变直径：10～20 mm 65个,21～30 mm 23个,31 mm以上36个,最大病变110 mm×100 mm。病变部位：直肠50个,乙状结肠25个,降结肠11个,横结肠10个,升结肠＋盲肠28个。黏膜腺管开口类型：Ⅲ型30个,其中17个为管状绒毛状腺瘤,12个为管状腺瘤;Ⅳ型56个,其中30个为绒毛状腺瘤,4个为黏膜内癌;Ⅴ型5个,其中2个为黏膜内癌,2个累及黏膜下层下1/3以下;Ⅱ型7个,其中5个为炎性增生性息肉,2个为锯齿状腺瘤（腺瘤性增生性息肉）：其余为ⅢL＋V型,其中23个为管状绒毛状腺瘤。符合适应证95例98个病变择期进行内镜下黏膜切除治疗,发生出血11例,均在操作过程中,无肠穿孔发生。结论大肠LST内镜形态具有一定特殊性,内镜下黏膜切除术是治疗在大肠的有效而安全的方法,可达到根治目的 。     

Comparison of cyclo-oxygenase 2 expression in colorectal serrated adenomas to expression in tubular adenomas and hyperplastic polyps

BACKGROUND AND AIMS: Serrated adenoma (SA) is a newly defined category of colorectal neoplasia that contains features of both adenoma and hyperplastic polyp, and has two patterns, hyperplastic and cerebriform patterns. Since cyclooxygenase 2 (COX-2) has been found upregulated in colorectal cancers and adenomas, we examined whether either the hyperplastic or cerebriform pattern of SA has the potential for tumor progression and should be a target for clinical treatment. PATIENTS AND METHODS: An immunohistochemical scoring system was used to compare COX-2 expression in colorectal SAs (n=79), tubular adenomas (n=66), and hyperplastic polyps (n=21). RESULTS: COX-2 scores were significantly higher in SA of the cerebriform pattern (n=44) than in SA of the hyperplastic pattern (n=35). There was no difference in COX-2 scores between SA of the cerebriform pattern and tubular adenoma. In SA accompanied by hyperplastic polyp (n=26) the hyperplastic components expressed little COX-2, the same as traditional hyperplastic polyps. COX-2 expression in the SA component was similar to that in pure SA. CONCLUSION: SA of the cerebriform pattern should be treated similarly as traditional tubular adenomas. COX-2 induction may additionally be involved in progression from hyperplastic polyp to SA.     

p53 overexpression in flat serrated adenomas and flat tubular adenomas of the colorectal mucosa

The expression of the p53 protein was investigated in flat serrated neoplasias as well as in other histological phenotypes of flat or exophytic hyperplasias or neoplasias of the colorectal, mucosa. A total of 104 such lesions were analyzed: 24 were flat serrated neoplasias (22 flat serrated adenomas and 2 flat serrated adenocarcinomas), 26 flat tubular adenomas, 17 flat hyperplastic polyps, 29 exophytic tubular and/or villous neoplasias (23 adenomas and 6 exophytic adenocarcinomas) and the remaining 8, exophytic hyperplastic polyps. Deparaffinized, rehydrated sections were treated immunohistochemically to detect those overexpressing the p53 protein. Lesions having slight (+), moderate (++) or intense (+++) staining were considered immunoreactive. The results showed that 50% of the flat serrated adenomas with low-grade dysplasia (LGD) and 66.7% of those with high-grade dysplasia (HGD) had p53 immunoreactivity. None of the flat tubular or of the exophytic adenomas with LGD expressed p53, but immunoreactivity was present in 61.5% of the flat tubular adenomas with HGD and in 52.3% of the exophytic adenomas with HGD. All adenocarcinomas had an intense p53 reaction. Weak p53 expression was demonstrated by 11.7% of the flat hyperplastic polyps but none of the exophytic polyps reacted. The occurrence of p53 expression in flat serrated adenomas with LGD suggested that, despite its low histological profile, one-half of those lesions could be biologically already committed to independent growth. The occurrence of p53 expression in nearly 12% of the flat hyperplastic polyps was totally unexpected and deserves further investigation. Flat serrated adenoma emerges as a novel, independent histological entity among the various phenotypes of flat neoplasias of the colorectal mucosa.     

Detection of colorectal adenomas by routine chromoendoscopy with indigocarmine

OBJECTIVES: Nonpolypoid adenomas, which can be important precursors of colorectal cancers, are difficult to find during routine colonoscopy. The aim of this study was to evaluate the usefulness of routine chromoendoscopy in Korea, where the incidence of colorectal cancer is low compared with western countries. METHODS: Colonoscopy with chromoendoscopy was performed in 74 consecutive patients (48 men, 26 women; mean age 53.0 yr). After a careful examination of the whole colon, a defined segment of the sigmoid colon and rectum (0-30 cm from the anal verge) was stained with 20 ml of 0.2% indigocarmine solution with a spraying catheter. Nonpolypoid lesions were classified as flat or depressed types. Biopsies were taken from all lesions detected before or after staining with indigocarmine. RESULTS: Indications for colonoscopy included routine check-up (21 patients), diarrhea or loose stool (14 patients), abdominal pain (12 patients), constipation (7 patients), bleeding (6 patients), and others (14 patients). Before staining, 58 lesions were found in 30 patients (43.2%). Histology showed tubular adenoma in 41 lesions, hyperplastic or inflammatory changes in 14 lesions, adenocarcinoma in 2 lesions, and villous adenoma in 1 lesion. After indigocarmine staining for normal-looking distal 30 cm colorectal mucosa, 176 lesions were found in 46 patients (62.2%). Histologically, 158 lesions were hyperplastic or inflammatory in nature, and 17 lesions (from 11 patients) were tubular adenomas. There was one serrated adenoma. Eighteen adenomas seen only after spraying indigocarmine were 2.6 +/- 0.6 mm in diameter, and all of them were classified as flat adenomas. There was no depressed-type adenoma. No adenoma with high grade dysplasia, villous histology, or cancer was found after staining. Presence of macroscopic adenomatous lesions or carcinoma before staining could not predict the existence of adenoma after staining. CONCLUSIONS: In a large proportion of patients, flat or depressed adenomas could be found after spraying indigocarmine for normal-looking colorectal mucosa in Korea. The clinical significance of these diminutive adenomas that can be found only after spraying contrast agent needs to be further investigated.     

High prevalence of sessile serrated adenomas with BRAF mutations: a prospective study of patients undergoing colonoscopy

BACKGROUND & AIMS: Sporadic colorectal cancers with a high degree of microsatellite instability are a clinically distinct subgroup with a high incidence of BRAF mutation and are widely considered to develop from serrated polyps. Previous studies of serrated polyps have been highly selected and largely retrospective. This prospective study examined the prevalence of sessile serrated adenomas and determined the incidence of BRAF and K-ras mutations in different types of polyps. METHODS: An unselected consecutive series of 190 patients underwent magnifying chromoendoscopy. Polyp location, size, and histologic classification were recorded. All polyps were screened for BRAF V600E and K-ras codon 12 and 13 mutations. RESULTS: Polyps were detected in 72% of patients. Most (60%) were adenomas (tubular adenomas, tubulovillous adenomas), followed by hyperplastic polyps (29%), sessile serrated adenomas (SSAs; 9%), traditional serrated adenomas (0.7%), and mixed polyps (1.7%). Adenomas were more prevalent in the proximal colon (73%), as were SSAs (75%), which tended to be large (64% >5 mm). The presence of at least one SSA was associated with increased polyp burden (5.0 vs 2.5; P < .0001) and female sex (P < .05). BRAF mutation was rare in adenomas (1/248 [0.4%]) but common in SSAs (78%), traditional serrated adenomas (66%), mixed polyps (57%), and microvesicular hyperplastic polyps (70%). K-ras mutations were significantly associated with goblet cell hyperplastic polyps and tubulovillous adenomas (P < .001). CONCLUSIONS: The prevalence of SSAs is approximately 9% in patients undergoing colonoscopy. They are associated with BRAF mutation, proximal location, female sex, and presence of multiple polyps. These findings emphasize the importance of identifying and removing these lesions for endoscopic prevention of colorectal cancer.     

结直肠锯齿状腺瘤内镜表现和病理学特征分析

目的探讨锯齿状腺瘤（SA）内镜下表现和病理学特征。方法回顾分析滨州医学院附属医院2000年1月～2008年5月检出的大肠息肉病例,了解SA的检出率、内镜形态和病理学特征。结果8726例肠镜检查共检出大肠息肉1062例（1457枚）,检出率为12．17％,其中SA32例（60枚）,检出率为0．37％,占息肉构成比为3．01％。SA直径〉1cm者占21．63％,明显大于增生性息肉（8．57％）;SA表现为有蒂息肉所占的比例（8．33％）略高于增生性息肉（5．71％）,但都低于腺瘤性息肉（40．84％）。SA癌变率介于管状腺瘤和绒毛状腺瘤之间,接近于管状绒毛状腺瘤。结论SA内镜形态、病理学特点提示SA是兼有增生性息肉形态学特征和腺瘤性息肉组织学特点的息肉,具有恶变潜能.