Differential diagnosis of colorectal polyps with respect to similar capabilities of white light colonoscopy and narrow-band imaging

Purpose

The responses of polyps to light essentially determine the diagnostic capability of an endoscopy system in differentiating adenomas from hyperplastic polyps. Compared with white light colonoscopy (WLC), narrow-band imaging (NBI) is expected to improve the diagnostic capability. The diagnostic capabilities of WLC and NBI are evaluated and compared based on the polyp responses.

Methods

The following WLC and NBI images were retrospectively reviewed and categorized: 195 images and polyps (89 WLC, 106 NBI) with the best visual quality were categorized in the best image group (BG), and 484 images of 242 polyps (both WLC and NBI) were categorized in the paired image group (PG). For each reflection of light used for WLC or NBI, the polyp responses were objectively expressed as reflection features. The reflection features were then used to establish a classification model for identifying adenomas. The diagnostic capability of reflection feature or classification model was measured by the area under the receiver operating characteristic curve (AUC).

Results

In both image groups, the diverse and heterogeneous features of the polyp responses enabled accurate identification of adenomas, regardless of the light source used for WLC and NBI. For differential diagnosis of adenomas and hyperplastic polyps, the WLC and NBI did not significantly differ in BG (AUC, 0.905 and 0.922, respectively; P?=?0.690) or in PG (AUC, 0.782 and 0. 769, respectively; P?=?0.755).

Conclusions

Using WLC and NBI as classification models is effective in differential diagnosis of colorectal polyps and exhibited similar capabilities.     

Comparative study of conventional colonoscopy, chromoendoscopy, and narrow-band imaging systems in differential diagnosis of neoplastic and nonneoplastic colonic polyps

AIM: To identify the feasibility of the narrow-band imaging (NBI) method compared with that of conventional colonoscopy and chromoendoscopy for distinguishing neoplastic and nonneoplastic colonic polyps. METHOD: This study enrolled consecutive patients who underwent colonoscopy using a conventional colonoscope between January and February 2006 at Chang-Gung Memorial Hospital, Linkou Medical Center, Taiwan. These 78 patients had 110 colorectal polyps. During the procedure, conventional colonoscopy first detected lesions, and then the NBI system was used to examine the capillary networks. Thereafter indigo carmine (0.2%) was sprayed directly on the mucosa surface prior to evaluating the crypts using a conventional colonoscope. The pit patterns were characterized using the classification system proposed by Kudo. Finally, a polypectomy or biopsy was performed for histological diagnosis. RESULTS: Of the 110 colorectal polyps, 65 were adenomas, 40 were hyperplastic polyps, and five were adenocarcinomas. The NBI system and pit patterns for all lesions were analyzed. For differential diagnosis of neoplastic (adenoma and adenocarcinoma) and nonneoplastic (hyperplastic) polyps, the sensitivity of the conventional colonoscope for detecting neoplastic polyps was 82.9%, specificity was 80.0% and diagnostic accuracy was 81.8%, significantly lower than those achieved with the NBI system (sensitivity 95.7%, specificity 87.5%, accuracy 92.7%) and chromoendoscopy (sensitivity 95.7%, specificity 87.5%, accuracy 92.7%). Therefore, no significant difference existed between the NBI system and chromoendoscopy during differential diagnosis of neoplastic and nonneoplastic polyps. CONCLUSION: The NBI system identified morphological details that correlate well with polyp histology by chromoendoscopy.     

利用窄带成像技术观察毛细血管形态在结直肠息肉样病变鉴别诊断中的价值

目的:探讨利用窄带成像技术(narrow bandimaging,NBI)观察毛细血管形态(capillarypatterns,CP)对结直肠息肉样病变鉴别诊断的价值.方法:75例患者接受NBI结肠镜检查共发现病变部位116处.根据Yoshiki的分型方法,将结直肠病变的CP分为6种:蜂窝状结构型、模糊结构型、网状结构型、密度增高型、不规则结构型、稀疏结构型.利用NBI下观察到的CP进行鉴别诊断,并与病理结果对照判定其敏感性、特异性及准确率.结果:在116例结直肠病变中增生性息肉毛细血管形态多表现为模糊结构型,而腺瘤性息肉的毛细血管形态表现为网状结构型和密度增高型,癌症的毛细血管形态多表现为不规则型和稀疏结构型.利用此分型方法鉴别肿瘤性病变和非肿瘤性病变的敏感性和特异性分别是94.6%和78.6%,准确性88.8%,阳性预测值(positive predictive value,PPV)88.6%,阴性预测值(negative predictivevalue,NPV)89.2%(P<0.01).同样,对于腺瘤性息肉和癌症的鉴别诊断的敏感性和特异性分别是100.0%和87.5%,准确性91.4%(P<0.01).将直径<10 mm的小息肉按毛细血管的有无进行鉴别诊断的敏感性和特异性分别是89.7%和80.5%,PPV81.4%,NPV89.2%,准确性85.0%(P<0.01).结论:NBI结肠镜观察结直肠病变CP对于鉴别肿瘤性病变与非肿瘤性病变,以及腺瘤性息肉与癌症具有可靠的诊断价值.对于直径<10 m m小息肉的肿瘤性及非肿瘤性的鉴别诊断方面NBI结肠镜也具有很好作用.     

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.     

Adenocarcinoma in solitary large hyperplastic polyp diagnosed by magnifying colonoscope: report of a case

We report a case of carcinoma in a hyperplastic polyp in a 78-year-old female that was diagnosed before resection using a magnifying colonoscope. The patient presented with fecal occult blood and underwent total colonoscopy, which revealed a 12-mm sessile polyp in the cecum. When seen in magnified view, an irregularly shaped pit was evident at the center of the polyp that was distinct from the asteroid-type pits observed over most of the lesion. We diagnosed this lesion as a hyperplastic polyp with a carcinoma component. The patient underwent endoscopic mucosal resection, and histologic section revealed a well-differentiated intramucosal adenocarcinoma in the hyperplastic polyp. Hyperplastic polyps of the colon are regarded as benign, nonneoplastic lesions. Few have reported carcinomas in or with hyperplastic polyps, and most of those were diagnosed after resection and histologic investigation. The literature suggests a precise observation and consideration of resection for large solitary hyperplastic polyps in the right side of the colon, because the risk of malignancy is high. Magnifying colonoscopy is helpful for observing the surface in detail and for correctly diagnosing and managing the lesion.     

Comparison of magnified pit pattern interpretation with narrow band imaging versus chromoendoscopy for diminutive colonic polyps: a pilot study

BACKGROUND: Chromoendoscopy can accurately differentiate neoplastic from nonneoplastic polyps in the colon. Narrow band imaging (NBI) has been described as "electronic chromoendoscopy," but it is unclear whether pit patterns seen with chromoendoscopy are identical to those with NBI. OBJECTIVE: Pilot study to compare features of diminutive polyps assessed with magnification NBI and chromoendoscopy. DESIGN: Prospective polyp series. SETTING: Single tertiary referral center in the United Kingdom. PATIENTS: Twenty patients seen for routine colonoscopy. INTERVENTION: Digital images of each polyp recorded with NBI and chromoendoscopy were subsequently assessed as single images in a random order and as paired polyp images by experienced European- and Japanese-trained endoscopists. MAIN OUTCOME MEASUREMENTS: Pit pattern (Kudo classification); vascular pattern intensity (weak, normal, strong); predicted histology; pit pattern and vessel network clarity (scale 1-3, 1 poor, 3 excellent). RESULTS: A total of 33 polyps 相似文献   

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.     

Magnifying Endoscopy with Indigo Carmine Contrast for Differential Diagnosis of Neoplastic and Nonneoplastic Colonic Polyps

This study describes the feasibility of magnifying colonoscopy with indigo carmine dye contrast to distinguish neoplastic and nonneoplastic colonic polyps. This study sampled consecutive patients undergoing colonoscopy using an Olympus CF240ZI from January to October 2000 at Chang-Gung Memorial Hospital, Lin-Kou Medical Center. This study analyzed a total of 270 polyps. Indigo carmine (0.2%) was sprayed directly on the mucosa surface before observing the crypts using a magnifying colonoscope (1.5x-100x). The pit patterns were described using the classification proposed by Kudo. Finally, polypectomy or biopsy was performed for histological diagnosis. The study identified 155 adenomas, 99 hyperplastic polyps, 9 adenocarcinomas, and 7 other nonneoplastic lesions (harmatoma, inflammatory polyps, and mucosal tag). The pit pattern was analyzed for all lesions. Further classification into neoplastic (adenoma and adenocarcinoma) and nonneoplastic (hyperplastic and others) polyps revealed 156 neoplastic and 14 nonneoplastic polyps among the type III to type V pits and 92 nonneoplastic and 8 neoplastic polyps among the type I and II pits. The sensitivity of type III to type V pits in detecting neoplastic polyps was 95.1%, with a specificity of 86.8% and diagnostic accuracy of 91.9%. The positive likelihood ratio was 7.3, and the negative likelihood ratio was 0.06. Magnifying colonoscopy with indigo carmine dye contrast provides morphological detail that correlates well with polyp histology. Small flat lesions with typical type II pit pattern should have minimal neoplastic risk, thus endoscopic resection is not necessary.     

黏膜表面形态特点对大肠息肉病理类型的预判价值

目的在高清非放大结肠镜下观察大肠息肉表面形态特点,与病理组织学诊断进行对照研究,评价息肉黏膜表面形态特点对大肠息肉病理类型的预判能力。方法对142例结直肠息肉患者330枚息肉样病变进行高清结肠镜检查并观察黏膜腺管开口形态,采用窄波带成像技术(narrow band imaging,NBI)观察黏膜表面血管形态(capillary pattern,CP),与息肉病理结果对照判定其敏感性、特异性及准确率。结果高清非放大结肠镜下联合黏膜腺管开口形态及黏膜表面血管形态判定息肉表面形态特点对鉴别肿瘤性与非肿瘤性病变的敏感性为88.2%,特异性为83.6%,阳性预测值为95.5%,阴性预测值为64.4%,准确度为87.3%,阳性相似比为5.4,阴性相似比为0.1。结论高清非放大结肠镜下贴近观察结合NBI显像观察息肉表面形态对于鉴别大肠息肉是否为肿瘤性有重要价值,与病理诊断有较好的符合率,有助于决定进一步治疗及随访方案。     

Risk for colon adenomas in patients with rectosigmoid hyperplastic polyps

OBJECTIVE: To determine whether hyperplastic polyps found in the rectosigmoid area of the colon are associated with proximal adenomas, and to judge whether patients with distal hyperplastic polyps found during sigmoidoscopy might benefit from full colonoscopy. DESIGN: Data on patients having colonoscopy collected prospectively according to a set protocol. The size and location of all polyps were noted, and all polyps were biopsied. SETTING: Two university hospitals. PATIENTS: One thousand eight hundred and thirty-six consecutive patients referred for colonoscopy between 31 December 1987 and 31 August 1989. RESULTS: Of the 970 patients who met eligibility requirements, 274 (28.3%) had adenomas and 108 (11.1%) had hyperplastic polyps. The proportion of patients with distal hyperplastic polyps and proximal adenomas (31.9%) was similar to the proportion of those without distal hyperplastic polyps (23.0%) (crude odds ratio, 1.57; 95% CI, 0.77 to 3.06). After adjusting for age and sex, the results were unchanged (adjusted odds ratio, 1.53; CI, 0.82 to 2.88). Patients with distal adenomas, on the other hand, were three times more likely to have proximal adenomas than those without distal adenomas (adjusted odds ratio, 3.42; CI, 1.99 to 5.88). CONCLUSIONS: Distal hyperplastic polyps are not strong predictors of risk for proximal adenomas. Based on the magnitude of the risk difference, we do not believe that finding a hyperplastic polyp during sigmoidoscopy justifies doing a full colonoscopy to search for proximal adenomas. Because rectosigmoid adenomas are associated with proximal adenomas, however, small polyps seen during sigmoidoscopy should be biopsied to determine their type. Colonoscopy should be reserved for patients who are proved to have adenomas.     

Pressure dye-spray: a simple and reliable method for differentiating adenomas from hyperplastic polyps in the colon

BACKGROUND: Based on 10 years of experience with chromoendoscopy, our hypothesis was that colonic adenomas can be differentiated from hyperplastic polyps by use of a high-pressure spray-jet of dye (pressure dye-spray). To test the accuracy of pressure dye-spray, classification of colonic polyps as adenomas and hyperplastic polyps by pressure dye-spray and ordinary colonoscopic findings (shape, size, and color surface appearance) were compared. METHODS: Pressure dye-spray chromoendoscopy was performed by using 0.035% indigo carmine, a spray-type cannula, and a water pump. Polyps were first classified as adenomas or hyperplastic polyps by ordinary colonoscopic findings. One or more pressure dye-spray bursts were then focused on the polyp from a distance of 1 to 2 cm. Polyps were classified as adenomas only if oozing of blood was evident; otherwise, they were classified as hyperplastic polyps. A histologic diagnosis was obtained for all polyps, and the results of ordinary colonoscopic findings and pressure dye-spray were compared. RESULTS: This study examined 1468 polyps (1201 adenomas, 267 hyperplastic polyps; mean diameter 4 mm). The sensitivities for polyp differentiation with pressure dye-spray and ordinary colonoscopic findings were, respectively, 97.9% and 73.4% (p < 0.0001); specificities were, respectively, 96.6% and 92.1% (p = 0.077). CONCLUSIONS: Pressure dye-spray was found to be a reliable technique for differentiation between adenomas and hyperplastic polyps.     

普通窄带成像内镜对结直肠增生性息肉和腺瘤的鉴别诊断价值

目的 分析普通窄带成像(NBI)内镜下结直肠增生性息肉与腺瘤腺管及微血管特征的差异,评价NBI的鉴别诊断价值.方法 将普通内镜下诊断结直肠息肉、病理检查证实为增生性息肉或腺瘤者纳入研究并进行NBI内镜检查.将腺管形态参照改良的工藤分型法分为A型和B型.将微血管形态分为3型,无微血管判为Ⅰ型,微血管沿腺管开口排列、粗细均匀判为Ⅱ型,微血管粗细不均、排列紊乱判为Ⅲ型.比较增生性息肉和腺瘤NBI图像中腺管形态和微血管形态特征的差异,同时对无放大NBI图像观察者间的一致性进行评价.结果 共87例患者的107个息肉(腺瘤73个、增生性息肉34个)进行普通NBI内镜检查.腺瘤组息肉最大径和表面分叶者比例明显高于增生性息肉组(P值分别=0.0023和0.0047).腺瘤组中B型腺管形态[86.3％(63/73)]及Ⅱ或Ⅲ型微血管形态[82.2％(60/73)]者较多.以B型腺管形态、Ⅱ型或Ⅲ型微血管中任一特征诊断腺瘤的敏感度、特异度、准确率分别为97.3％、82.4％、92.5％.以B型腺管形态联合Ⅱ型或Ⅲ型微血管诊断腺瘤的敏感度、特异度、准确率分别为71.2％、91.2％、77.6％.观察者间一致性评价平均Kappa值为0.761.结论 普通NBI内镜下结直肠腺瘤和增生性息肉的微血管特征和腺管特征存在差异,依据以上两方面可在NBI内镜下实时初步鉴别腺瘤和增生性息肉.     

DIAGNOSTIC ACCURACY OF PIT PATTERN AND VASCULAR PATTERN ANALYSES IN COLORECTAL LESIONS

Background: The aim of this prospective study is to compare the usefulness of magnifying narrow band imaging (NBI) and magnifying chromoendoscopy in the diagnosis of colorectal lesions. Methods: The subjects were 1185 patients who underwent a complete colonoscopic examination and endoscopic or surgical treatment, from January 2006 to February 2008. A total of 1473 lesions were evaluated (53 hyperplastic polyps, 1317 adenomas, 103 submucosally invasive cancers). The digital images with NBI or chromoendoscopy were recorded and diagnosed independently from each other by two endoscopists who were blinded to the final pathological diagnosis. Results: We could differentiate between neoplastic and non‐neoplastic lesions with sensitivity of 88.9%, specificity of 98.5% and accuracy of 98.2% according to the vascular pattern. By recognizing an irregular or sparse pattern with NBI, massively invasive submucosal cancer could be diagnosed with the sensitivity and specificity of 94.9% and 76.0%. Using chromoendoscopy, we could differentiate between neoplastic and non‐neoplastic lesions with sensitivity of 86.8% and specificity of 99.2%. We were able to differentiate between massively invasive cancers and slightly invasive cancers using the pit patterns with sensitivity of 89.7% and specificity of 88.0%. The specificity was superior to that of NBI colonoscopy. Conclusion: Both NBI and chromoendoscopy can be useful for distinguishing between neoplastic and non‐neoplastic lesions. In the diagnosis of submucosal cancer, pit pattern diagnosis was slightly superior to vascular pattern diagnosis. It is desirable to perform chromoendoscopy in addition to NBI for distinguishing between slightly and massively invasive submucosal cancer lesions and determining the treatment.     

Narrow-band imaging in the colon: limitations and potentials

Narrow-band imaging (NBI) is a new endoscopic technology that highlights surface structures and superficial mucosal capillaries during colonoscopy at a single push of a button. NBI has a high sensitivity and specificity for differentiating neoplastic and non-neoplastic polyps by means of mucosal and capillary patterns. It is also useful in determining the invasion depth of early colorectal cancers and evaluating free margins after endoscopic resection. However, it has not been shown to improve the adenoma detection rate compared with white-light endoscopy. Although narrow-band imaging is now available commercially, its role in routine clinical practice during colonoscopy is not well defined. The difficulties in interpreting results partly relate to different NBI nomenclatures used in classifying colonic adenomas and their lack of standardization. Future research should focus on establishing a reliable NBI nomenclature for capillary patterns, defining the learning curve and interobserver variation, and validating the effectiveness of NBI in routine colonoscopy.     

Spatial clustering of multiple hyperplastic,adenomatous, and malignant colonic polyps in individual patients

Analysis of relative polyp locations in 426 consecutive patients with multiple colonic polyps found on colonoscopy showed novel findings. First, synchronous and metachronous neoplastic polyps showed spatial clustering in individual patients. For example, patients with their largest neoplasm in the cecum or proximal ascending colon, had 34.3 percent±4.6 percent (standard error) of their other colonic neoplasms in the same location. Second, hyperplastic polyps showed spatial clustering in individuals that was statistically significantly greater than expected from the increased hyperplastic polyp concentration in the rectum and sigmoid. Third, hyperplastic polyps showed spatial clustering with neoplastic polyps; this clustering was similar in magnitude to clustering for exclusively hyperplastic or neoplastic polyps. In contrast, lipomas were not spatially clustered with hyperplastic and neoplastic polyps. The magnitude of clustering between hyperplas and neoplasia showed a closer association between these histologic types than previously appreciated. Because of clustering, regions with prior polyps appear to merit closer surveillance. These findings suggest clinical study, using a randomized controlled clinical trial, of whether a patient who had only rectal and sigmoid adenomas on initial and follow-up colonoscopy should have surveillance with flexible sigmoidoscopy alternating annually with colonoscopy. A patient with a prior cecal adenoma should have surveillance only with a complete colonoscopy or adequate cecal views on barium enema.     

Diagnostic value of high-resolution micro-endoscopy for the classification of colon polyps

AIM: To study a new imaging equipment, highresolution micro-endoscopy(HRME), in the diagnosis and pathological classification of colon polyps.METHODS: We selected 114 specimens of colon polyps, 30 of which were colon polyps with known pathological types and 84 that were prospective polyp specimens; 10 normal colon mucosa specimens served as controls. We obtained images of 30 colon polyp specimens with known pathological types using HRME and analyzed the characteristics of these images to develop HRME diagnostic criteria for different pathological types of colon polyps. Based on these criteria, we performed a prospective study of 84 colon polyp specimens using HRME and compared the results with those of the pathological examination to evaluate the diagnostic value of HRME in the pathological classification of different types of colon polyps. RESULTS: In the 30 cases of known pathological type of colon polyp samples, there were 21 cases of adenomatous polyps, which comprised nine cases of tubular adenoma, seven cases of villous adenoma and five cases of mixed adenomas. The nine cases of non-adenomatous polyps included four cases of inflammatory polyps and five cases of hyperplastic polyps five. Ten cases of normal colonic mucosa were confirmed pathologically. In a prospective study of 84 cases using HRME, 23 cases were diagnosed as inflammatory polyps, 11 cases as hyperplastic polyps, 18 cases as tubular adenoma, eight cases as villous adenoma and 24 cases as mixed adenomas. After pathological examination, 24 cases were diagnosed as inflammatory polyps, 11 cases as hyperplastic polyps, 19 cases as tubular adenoma, eight cases as villous adenoma and 22 cases as mixed adenomas. Compared with the pathological examinations, the sensitivities, specificities, accuracies, and positive and negative predictive values of HRME in diagnosing inflammatory polyps(87.5%, 96.7%, 94.0%, 91.3% and 95.1%), hyperplastic polyps(72.7%, 95.9%, 92.9%, 72.7% and 95.9%), tubular adenomas(73.7%, 93.8%, 89.3%, 77.8% and 92.4%), villous adenomas(75.0%, 97.4%, 95.2%, 75.0% and 97.4%), and mixed adenomas(75.0%, 93.3%, 88.1%, 81.8% and 90.3%) were relatively high.CONCLUSION: HRME has a relatively high diagnostic value in the pathological classification of colon polyps. Thus, it may be an alternative to confocal microendoscopy in lower-resource or community-based settings.     

Study of the gastric mucosal background in patients with gastric polyps

The characteristics of gastric mucosal patterns in the polyp-bearing stomach were investigated by the endoscopic Congo red test and systemic four-points biopsy in 46 patients with hyperplastic polyps and 21 patients with gastric adenomas. In addition, function of the stomach in these patients was assessed by determination of gastric acidity and fasting serum gastrin level and by gastrin response test to a beef extract. In the investigation of the gastric mucosal pattern in hyperplastic polyp patients, Type A gastritis (involving the corpus but sparing the antrum) was most frequently found. On the other hand, extensive intestinal metaplasia from the pyloric antrum to the corpus was most often noted in the adenoma-bearing stomach. Hypergastrinemia was more marked in hyperplastic polyp patients, and may be involved in the pathogenesis of hyperplastic polyps. Attention should be paid to the detection of cancer in areas without polyps during endoscopic observation and reexamination of patients. On these occasions, the characteristics of the background mucosa for each type of polyp should be kept in mind.     

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.     

Serrated adenoma of the colorectum: colonoscopic and histologic features

BACKGROUND: Serrated adenoma is a recently recognized epithelial neoplasm of the colorectum. The aim of this study is to clarify the colonoscopic features of serrated adenomas. METHODS: The endoscopic findings for 52 serrated adenomas of the colorectum were investigated; these were then divided into three groups according to surface features. The histologic type (tubular, tubulovillous or villous) and the incidence of high-grade dysplasia were compared among the three groups. RESULTS: The surface under chromoscopy showed a hyperplastic pattern in 17 lesions, a cerebriform pattern in 18 lesions and a combined pattern in 17 lesions. The tubular type of serrated adenoma was predominant in the hyperplastic pattern group (94%), whereas the tubulovillous or villous histologic types were frequent in the cerebriform pattern (89%) and combined pattern (82%) groups. High-grade dysplasia was found in 18% of the combined pattern adenomas; the incidence was lower in hyperplastic (6%) or cerebriform pattern (0%) adenomas. CONCLUSIONS: Surface features of serrated adenomas have a close correlation with their histologic type. A combined hyperplastic-cerebriform surface pattern under chromoscopy was seen only in serrated adenomas.     

White light endoscopy, narrow band imaging and chromoendoscopy with magnification in diagnosing colorectal neoplasia

AIM: To evaluate the sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of 3 different techniques: high resolution white light endoscopy (WLE), Narrow Band Imaging (NBI) and Chromoendoscopy (CHR), all with magnification in differentiating adenocarcinomas, adenomatous and hyperplastic colorectal polyps.METHODS: Each polyp was sequentially assessed first by WLE, followed by NBI and finally by CHR. Digital images of each polyp with each modality were taken and stored. Biopsies or polypectomies were then performed followed by blinded histopathological analysis. Each image was blindly graded based on the Kudo’s pit pattern (KPP). In the assessment with NBI, the mesh brown capillary network pattern (MBCN) of each polyp was also described. The Sn, Sp, PPV and NPV of differentiating hyperplastic (Type I & II-KPP, Type I-MBCN) adenomatous (Types III, IV-KPP, Type II-MBCN) and carcinomatous polyps (Type V-KPP, Type III-MCBN) was then compared with reference to the final histopathological diagnosis.RESULTS: A total of 50 colorectal polyps (5 adenocarcinomas, 38 adenomas, 7 hyperplastic) were assessed. CHR and NBI [KPP, MBCN or the combined classification (KPP & MBCN)] were superior to WLE in the prediction of polyp histology (P < 0.001, P = 0.002, P = 0.001 and P < 0.001, respectively). NBI, using the MBCN pattern or the combined classification showed higher numerical accuracies compared to CHR, but this was not statistically significant (P = 0.625, 0.250).CONCLUSION: This feasibility study demonstrated that this combined classification with NBI could potentially be useful in routine clinical practice, allowing the endoscopist to predict histology with higher accuracies using a less cumbersome and technically less challenging method.