Esophageal adenocarcinoma with white opaque substance observed by magnifying endoscopy with narrow band imaging

White opaque substance (WOS) is observed in the gastric neoplasia of 0‐IIa type using magnifying endoscopy with narrow band imaging (NBI‐ME). Colonic and duodenal neoplasms with WOS have also been reported. Immunohistochemical examination with adipophilin reveals WOS in gastric neoplasms as lipid droplets, and WOS is specific for neoplasm with intestinal or gastrointestinal phenotype. We herein report a case of adenocarcinoma of the esophagogastric junction with WOS. A male patient in his sixties was found by esophagogastroduodenoscopy to have an esophageal elevated lesion. NBI‐ME showed whitish deposits that looked similar to WOS in gastric neoplasms. The patient underwent endoscopic submucosal dissection and the lesion was resected in a single piece. This tumor had diffuse positivity for adipophilin and gastrointestinal phenotype.     

Usefulness of magnifying endoscopy with narrow-band imaging for determining gastric tumor margin

Background and Aim: Magnifying endoscopy with narrow‐band imaging (ME‐NBI) enhances images of the irregular mucosal structures and microvessels of gastric carcinoma, and could be useful for determining the margin between cancerous and non‐cancerous mucosa. We evaluated the usefulness of ME‐NBI for determining the tumor margin compared with indigocarmine chromoendoscopy (ICC). Methods: The subjects were 110 patients (with 118 lesions) who underwent endoscopic submucosal dissection for gastric tumors. They were randomized into ME‐NBI and ICC groups. Marking was carried out by electrocautery with the tip of a high‐frequency snare at the tumor margins determined by each observation. The distance from the marking dots to the tumor margin was measured histopathologically in the resected specimens. Marking was diagnosed as accurate if the distance was less than 1 mm. Results: Of the 118 gastric lesions, 55 were allocated to the ME‐NBI group, and 63 to the ICC group. Seventeen lesions in the ME‐NBI group and 18 lesions in the ICC group were excluded because the distance from the marking dots to the tumor margin was immeasurable histopathologically. Thirty‐eight lesions in the ME‐NBI group and 45 lesions in the ICC group were evaluated. The rate of accurate marking of the ME‐NBI group was significantly higher than that of the ICC group (97.4% vs 77.8%, respectively; P‐value = 0.009). Conclusion: Magnifying endoscopy with narrow‐band imaging can identify gastric tumor margins more clearly than ICC.     

Surveillance using trimodal imaging endoscopy after endoscopic submucosal dissection for superficial gastric neoplasia

AIM:To evaluate the effectiveness of trimodal imaging endoscopy(TME)to detect another lesion afterendoscopic submucosal dissection(ESD)for superficial gastric neoplasia(SGN).METHODS:Surveillance esophagogastroduodenoscopy(EGD)using a TME was conducted in 182 patients that had undergone ESD for SGN.Autofluorescence imaging(AFI)was conducted after white-light imaging(WLI).When SGN was suspicious,magnifying endoscopy with narrow-band imaging(ME-NBI)was conducted.Final diagnoses were made by histopathologic findings of biopsy specimens.The detection rates of lesions in WLI,AFI,and NBI,and the characteristics of lesions detected by WLI and ones missed by WLI but detected by AFI were examined.The sensitivity,specificity,and accuracy of endoscopic diagnosis using WLI,AFI and ME-NBI were evaluated.RESULTS:In 242 surveillance EGDs,27 lesions were determined pathologically to be neoplasias.Sixteen early gastric cancers and 6 gastric adenomas could be detected by WLI.Sixteen lesions were reddish and 6were whitish.Five gastric neoplasias were missed by WLI but were detected by AFI,and all were whitish and protruded gastric adenomas.There was a significant difference in color and pathology between the two groups(P=0.006).Sensitivity,specificity and accuracy in MENBI were higher than those in both WLI and AFI.Specificity and accuracy in AFI were lower than those in WLI.CONCLUSION:Surveillance using trimodal imaging endoscopy might be useful for detecting another lesion after endoscopic submucosal dissection for superficial gastric neoplasia.     

Diagnosis of undifferentiated type early gastric cancers by magnification endoscopy with narrow-band imaging

Background and Aims: The diagnostic use of magnification endoscopy with narrow‐band imaging (ME‐NBI) to assess histopathologically undifferentiated‐type early gastric cancers (UD‐type EGCs) is not well elucidated. The purpose of this study was to examine the comparative relationship between ME‐NBI images and histopathological findings in UD‐type EGCs. Methods: We analyzed 78 consecutive cases of UD‐type EGCs ≤ 20 mm in diameter that underwent ME‐NBI ≤ 2 weeks prior to resection. The ME‐NBI images were compared with histopathological findings following either endoscopic submucosal dissection (ESD) or surgery. Applying the comparative results, we prospectively evaluated the success of identifying the lateral extent of UD‐type EGCs resected by ESD in additional consecutive cases. Results: Lesions with preserved but irregular surface microstructures (S‐type based on ME‐NBI) showed mucosal atrophy and corresponded histologically to the non‐whole‐layer type of intramucosal cancer (24/24, 100%). Lesions with an irregular microvasculature type (V‐type, for example, corkscrew pattern) or mixed type upon ME‐NBI corresponded histopathologically to the non‐whole‐layer type of intramucosal cancer (15/54, 27.8%), the whole‐layer type of intramucosal cancer (27/54, 50.0%) or submucosal (sm) invasion cancer (12/54, 22.2%). Applying these comparative results, we used ME‐NBI to successfully predict the lateral extent of cancer, which corresponded to the histopathological lateral extent in all 18 additional consecutive UD‐type EGCs resected by ESD. Conclusions: ME‐NBI images of UD‐type EGCs were very closely related to the histopathological findings. Thus, ME‐NBI can be useful in the pretreatment assessment of the histopathological patterns of cancer development and the lateral extent of such lesions.     

Clinicopathological characteristics of abnormal micro-lesions at the oro-hypopharynx detected by a magnifying narrow band imaging system

Background: Narrow band imaging (NBI) with magnifying endoscopy (NBI‐ME) allows the detection of abnormal micro‐lesions smaller than 5 mm in diameter in the oro‐hypopharynx that could not be visualized previously. The purpose of the present study was to clarify the clinicopathological characteristics of abnormal micro‐lesions of the oro‐hypopharynx detected by NBI‐ME Methods: Of the 62 lesions detected by NBI‐ME, 40 abnormal micro‐lesions in 37 patients were removed by endoscopic treatment and were pathologically evaluated. We reviewed the medical records of patients with these lesions and investigated the relationship between NBI‐ME findings and pathological findings. Results: Pathological examination revealed the following: high‐grade intraepithelial neoplasia (HGIN) in nine (23%) lesions, low‐grade intraepithelial neoplasia (LGIN) in 22 (55%), pharyngitis in seven (18%) and papilloma in two (5%). Two NBI‐ME findings, high microvascular density (MVD) and a brownish area (BA), were recognized more frequently as the grade of malignancy advanced. The likelihood ratio (confidential interval) for having HGIN in the patients with both MVD and BA was 13 (3.62–127). Conclusions: The pathological diagnosis of abnormal micro‐lesions ranged from pharyngitis to HGIN. High MVD and BA may be important findings for grading the malignancy of abnormal micro‐lesions.     

Disección endoscópica de submucosa para neoplasias gástricas superficiales en dos hospitales de referencia en Brasil: ¿se pueden igualar los resultados de Japón y Corea del Sur?

Introduction and aimsEndoscopic submucosal dissection (ESD) in the treatment of superficial neoplasias of the gastrointestinal tract is currently one of the greatest advances in therapeutic endoscopy. Due to its high technical complexity, it is not yet a routine procedure in Latin America. The aim of the present study was to present the experience in Brazil with ESD in superficial gastric neoplasias, based on training received from Japanese experts.Materials and methodsA retrospective study was conducted, in which information was prospectively collected from a database that included all patients that underwent ESD due to superficial gastric neoplasias at two endoscopy referral centers in Brazil, within the time frame of June 2008 to June 2019. En bloc, complete, and curative resection rates were calculated, along with the local recurrence rate and adverse events.ResultsA total of 103 ESDs for superficial gastric neoplasias were performed during the study period. Eighty of those patients (77.6%) presented with early malignant gastric neoplasias or premalignant lesions (adenocarcinoma: 52.5%, high-grade dysplasia: 27.5%, low-grade dysplasia: 16.3%, and neuroendocrine tumors: 3.8%). Overall en bloc and complete resection rates for the superficial gastric neoplasias were 96.3% and 92.5%, respectively, whereas the curative resection rate based on expanded criteria was 76%.ConclusionsESD for the treatment of superficial gastric neoplasias is a safe and effective therapeutic modality in Latin America, with results similar to those shown in the most representative Japanese studies.     

Autofluorescence videoendoscopy system using the SAFE‐3000 for assessing superficial gastric neoplasia

Background: Autofluorescence (AF) videoendoscopy has an advantage over ordinary videoendoscopy in the diagnosis of gastric neoplasias, and the aim of the present study was to evaluate the effectiveness of using the SAFE‐3000 videoendoscopy system to diagnose superficial gastric neoplasias. Methods: Ordinary videoendoscopy, AF videoendoscopy, and chromoendoscopy (CE) were used to diagnose the tumor existence and extent in 14 patients with gastric adenoma, 40 patients with intestinal‐type early gastric cancer (EGC) (10 protruded, and 30 depressed), and nine patients with diffuse‐type EGC. The diagnostic accuracies of the three kinds of images were evaluated by comparison with the results of histopathological assessment of resected specimens. Results: For gastric adenomas the diagnostic accuracy between the AF images and white light (WL) images did not differ significantly, and for protruded intestinal‐type EGCs and diffuse‐type EGCs the diagnostic accuracy did not differ significantly between any of the types of images. For depressed intestinal‐type EGCs, the diagnostic accuracy of AF images tended to be higher than that of the WL images (P < 0.05) and it was not significantly different from that of the CE images. The detection rate of pink or orange color in AF images was significantly higher for protruded intestinal‐type EGCs than gastric adenomas (P = 0.005), depressed intestinal‐type EGCs (P < 0.001), and diffuse‐type EGCs (P = 0.027). Conclusions: Autofluorescence videoendoscopy using the SAFE‐3000 system for gastric neoplasias might be useful for diagnosing depressed intestinal‐type early gastric cancers. The detection of orange or pink color in AF images may be efficacious in discriminating protruded intestinal‐type early gastric cancers from gastric adenomas.     

MAGNIFYING ENDOSCOPIC OBSERVATION WITH NARROW BAND IMAGING FOR SPECIALIZED INTESTINAL METAPLASIA IN BARRETT'S ESOPHAGUS WITH SPECIAL REFERENCE TO LIGHT BLUE CRESTS

Aim: Barrett's esophagus (BE) with specialized intestinal metaplasia (SIM) is at high risk of esophageal adenocarcinoma. Magnified endoscopy with narrow band imaging (ME‐NBI) can be useful for detecting this condition. In addition to pit patterns, light blue crests (LBC), blue‐whitish patchy areas on the metaplastic epithelia of the stomach, can predict SIM in BE under ME‐NBI observation. Methods: A total of 54 patients with BE underwent ME‐NBI to identify IM pits (tubular and villous pits) and LBC. Biopsy samples were taken for histological evaluation of IM, immunohistochemical staining for CD10, MUC2 and MUC5AC antigen, transmission electron microscopy and real‐time polymerase chain reaction (RT‐PCR) analysis of CD10 mRNA expression. Results: IM pit pattern with ME‐NBI for the diagnosis of IM yielded acceptable sensitivity, specificity and accuracy at 92%, 77% and 83%, respectively. However, the sensitivity, specificity and accuracy of LBC with ME‐NBI for IM were comparably high at 79%, 97% and 89%, respectively. Upon immunohistochemistry, all 19 metaplastic epithelia of LBC‐positive BE showed immunoreactivity against anti‐MUC2 antibody, whereas CD10 antigen was identified in 11 of the 19 LBC‐positive BE. Brush borders were seen on IM epithelia using electron microscopy. On real‐time PCR analysis, CD10 mRNA levels in the LBC‐positive BE were higher compared to those in the LBC‐negative BE. Conclusion: The appearance of LBC can be an accurate sign to predict SIM in BE and may be associated with high CD10 expression, possibly along with brush borders.     

Diagnosis of Helicobacter pylori‐related chronic gastritis,gastric adenoma and early gastric cancer by magnifying endoscopy

Evaluating the prevalence and severity of gastritis by endoscopy is useful for estimating the risk of gastric cancer (GC). Moreover, understanding the endoscopic appearances of gastritis is important for diagnosing GC due to the fact that superficial mucosal lesions mimicing gastritis (gastritis‐like lesions) are quite difficult to be detected even with optimum preparation and the best technique, and in such cases tissue biopsy is often not very accurate for the diagnosis of gastric epithelial neoplasia. Magnifying endoscopy is a highly accurate technique for the detection of early gastric cancer (EGC). Recent reports have described that various novel endoscopic markers which, visualized by magnifying endoscopy with image‐enhanced system (ME‐IEE), can predict specific histopathological findings. Using ME‐IEE with vessels and surface classification system (VSCS) may represent an excellent diagnostic performance with high confidence and good reproducibility to the endoscopists if performed under consistent conditions, including observation under maximal magnification. The aim of this review was to discuss how to identify high‐risk groups for GC by endoscopy, and how to detect effectively signs of suspicious lesions by conventional white light imaging (C‐WLI) or chromoendoscopy (CE). Furthermore, to characterize suspicious lesions using ME‐IEE using the criteria and classification of EGC based upon VSCS.     

Significance of each narrow‐band imaging finding in diagnosing squamous mucosal high‐grade neoplasia of the esophagus

Background and Aim: Although narrow‐band imaging (NBI) is used increasingly in clinical situations, the significance of each NBI finding has not been investigated. The primary endpoint of the present study was to identify the significant NBI findings to diagnose esophageal mucosal high‐grade neoplasia. Methods: Between August 2007 and January 2009, we detected 59 new superficial esophageal lesions. The video images of NBI were recorded digitally. NBI findings such as brownish dots (dilated intra‐epithelial papillary capillary loop [IPCL]), tortuous IPCL, elongated IPCL, caliber change in IPCL, variety in IPCL shapes, demarcation line, brownish epithelium, and protrusion or depression were evaluated using the video images. The association between each NBI finding and diagnosis of mucosal high‐grade neoplasia, and intra‐ and interobserver agreement was evaluated. Results: In univariate analysis, brownish epithelium, brownish dots, tortuous IPCL, variety in IPCL shapes and demarcation line were associated significantly with diagnosis of mucosal high‐grade neoplasia. In multivariate analysis, brownish epithelium and brownish dots were confirmed to be independent factors. Odds ratios were 25.5 (95% confidence interval [CI]: 2.4–268) for brownish epithelium and 19.3 (95% CI: 1.8–207.7) for brownish dots. Intraobserver agreement was substantial for brownish epithelium and brownish dots. Interobserver agreement was moderate in brownish epithelium and brownish dots. Conclusions: Brownish epithelium and brownish dots were confirmed to be significant and reproducible NBI findings in the diagnosis of squamous mucosal high‐grade neoplasia of the esophagus. Initial assessment of esophageal lesions should be done based on these findings.     

Original article: Prospective evaluation of narrow‐band imaging endoscopy for screening of esophageal squamous mucosal high‐grade neoplasia in experienced and less experienced endoscopists

Narrow‐band imaging (NBI) is a novel, noninvasive optical technique that uses reflected light to visualize the organ surface. However, few prospective studies that examine the efficacy of NBI screening for esophageal cancer have been reported. To compare the diagnostic yield of NBI endoscopy for screening of squamous mucosal high‐grade neoplasia of the esophagus between experienced and less experienced endoscopists. Patients with a history of esophageal neoplasia or head and neck cancer received NBI endoscopic screening for esophageal neoplasia followed by chromoendoscopy using iodine staining. Biopsy specimens were taken from iodine‐unstained lesions and the histological results of mucosal high‐grade neoplasias served as the reference standard. The primary outcome was the sensitivity of NBI for detecting new lesions. The secondary outcome was the positive predictive value of NBI and the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of NBI in a per lesion basis. A total of 350 patients (170 by experienced endoscopists and 180 by less experienced endoscopists) underwent endoscopic examination. A total of 42 new mucosal high‐grade neoplastic lesions (25 in the experienced endoscopist group and 17 in the less experienced endoscopist group) were detected. In the per‐lesion‐based analysis, the sensitivity was significantly higher in the experienced endoscopist group (100%; 25/25) compared with the less experienced endoscopist group (53%; 9/17) (P < 0.001). The positive predictive value of NBI was higher in the experienced endoscopist group than in the less experienced endoscopist group (45%, 25/55 vs. 35%, 9/26), although the difference was not significant (P = 0.50). The sensitivity of NBI in the less experienced endoscopist group was 43% in the former half of patients, and increased to 60% in the latter half of patients. In the per‐patient‐based analysis, the sensitivity of NBI was significantly higher in the experienced endoscopist group (100%) than in the less experienced endoscopist group (100 vs. 69%, respectively; P = 0.04). The positive predictive values of the experienced endoscopist group and the less experienced endoscopist group were similar, and were 48 and 47%, respectively. In conclusion, compared with the gold standard of chromoendoscopy with iodine staining, the sensitivity of NBI for screening of mucosal high‐grade neoplasia was 100% with the experienced endoscopists but was low with the less experienced endoscopists. Electronic chromoendoscopy with NBI is a promising screening tool in these high‐risk patients with esophageal mucosal high‐grade neoplasia, particularly when performed by endoscopists with experience of using NBI.     

Narrow‐band imaging (NBI) magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team

Many clinical studies on narrow‐band imaging (NBI) magnifying endoscopy classifications advocated so far in Japan (Sano, Hiroshima, Showa, and Jikei classifications) have reported the usefulness of NBI magnifying endoscopy for qualitative and quantitative diagnosis of colorectal lesions. However, discussions at professional meetings have raised issues such as: (i) the presence of multiple terms for the same or similar findings; (ii) the necessity of including surface patterns in magnifying endoscopic classifications; and (iii) differences in the NBI findings in elevated and superficial lesions. To resolve these problems, the Japan NBI Expert Team (JNET) was constituted with the aim of establishing a universal NBI magnifying endoscopic classification for colorectal tumors (JNET classification) in 2011. Consensus was reached on this classification using the modified Delphi method, and this classification was proposed in June 2014. The JNET classification consists of four categories of vessel and surface pattern (i.e. Types 1, 2A, 2B, and 3). Types 1, 2A, 2B, and 3 are correlated with the histopathological findings of hyperplastic polyp/sessile serrated polyp (SSP), low‐grade intramucosal neoplasia, high‐grade intramucosal neoplasia/shallow submucosal invasive cancer, and deep submucosal invasive cancer, respectively.     

Magnifying endoscopy with narrow band imaging for diagnosis of colorectal tumors

BACKGROUND: Narrow band imaging (NBI) uses optical filters for red-green-blue sequential illumination and narrows the bandwidth of spectral transmittance. OBJECTIVE: This study aimed to clarify the clinical usefulness of NBI magnification in assessment of pit patterns for diagnosis of colorectal tumors. DESIGN: This was a retrospective study. SETTING: Department of Endoscopy, Hiroshima University Hospital. PATIENTS AND MAIN OUTCOME MEASUREMENTS: A total of 148 colorectal lesions, 16 hyperplasias, 84 tubular adenomas, and 48 early carcinomas were examined and diagnosed histologically. Mean size of lesions was 15.6+/-7.28 mm. Lesions were observed first under NBI magnification without chromoendoscopy and then under standard magnification with chromoendoscopy, and pit patterns were recorded. Results of NBI magnification were compared with those of standard magnification with chromoendoscopy to assess the clinical usefulness of NBI magnification for diagnosing colorectal neoplasia. RESULTS: Correspondence between the two diagnostic methods was 88% (14/16) for type II, 100% (2/2) for type IIIs, 98% (73/75) for type IIIl, 88% (7/8) for type IV, 78% (25/32) for type Vi, and 100% (3/3) for type Vn pit patterns. NBI depicted brownish change on the basis of surface capillaries in 6% (1/16) of hyperplasia and 99% (83/84) of tubular adenomas. This difference in color depiction was significant. LIMITATIONS: This study was performed in single center. CONCLUSIONS: Determination of pit patterns of colorectal neoplasias by NBI magnification was nearly the same as that by standard magnification with chromoendoscopy. Furthermore, NBI can distinguish neoplastic and nonneoplastic lesions without chromoendoscopy.     

Mucin and differentiation in Epstein-Barr virus-associated gastric carcinoma

BACKGROUND/AIMS: Epstein-Barr virus (EBV) is present in roughly 1 in 10 cases of gastric carcinoma, particularly in undifferentiated adenocarcinomas. To clarify the histological developmental processes in EBV-associated gastric carcinoma, we investigated the presence of EBV infection, changes in the degree of differentiation within lesions, and mucin phenotypes of gastric carcinomas. METHODOLOGY: We had already examined 124 gastric carcinomas using in situ hybridization for EBV-encoded small RNA1 (EBER-1) and 12 lesions were EBER-1-positive. From these lesions we selected 8 carcinomas positive for EBER-1, and then chose 16 EBER-1-negative carcinomas as controls. Hematoxylin and eosin (H&E) stained specimens were examined for changes in histological type within each lesion. Mucin phenotypes of the specimens were determined using human gastric mucin (HGM), MUC2 and CD10 immunostaining. RESULTS: Of the EBER-1-positive lesions, 50% exhibited the gastric type mucin phenotype, whereas only 19% of the EBER-1-negative lesions were of the gastric phenotype. Changes in the histological type were seen within 75% of the EBER-1-positive lesions and within 62.5% of the EBER-1-negative lesions. CONCLUSIONS: The gastric mucin phenotype tended to be more common in the EBV-associated gastric carcinomas. The influence of EBV infection on the change in the histological type within the lesion was considered to be slight.     

Preliminary study of magnetically controlled capsule gastroscopy for diagnosing superficial gastric neoplasia

BackgroundMagnetically controlled capsule gastroscopy (MCCG) is a newly developed non-invasive method designed for gastric examination. Although favorable diagnostic accuracy has been reported, there is little if any data about its ability to diagnose gastric cancer.AimsTo compare the detectability of superficial gastric neoplasia by MCCG and gastroscopy.MethodsThis study was a self-controlled comparison study. Ten subjects diagnosed with superficial gastric neoplasia and scheduled to undergo endoscopic submucosal dissection (ESD) at a tertiary hospital were prospectively invited for an MCCG examination. The diagnostic agreement of MCCG, ESD and pathology were compared, including location, size and endoscopic appearance of the lesions.ResultsOf the 10 enrolled patients, 6 were confirmed as having early gastric cancer/high-grade intraepithelial neoplasia, 2 gastric low-grade intraepithelial neoplasia (LGIN), 1 tubular adenoma with LGIN and 1 neuroendocrine tumor. The per-patient and per-lesion sensitivities of MCCG for superficial gastric neoplasia detection were 100% and 91.7%. Location and size of the lesions were compared favorably to gastroscopy whilst one cardiac lesion was missed. Endoscopic appearances of these lesions observed on MCCG and EGD demonstrated good consistency. No adverse events were observed.ConclusionWith good gastric preparation and careful examination of stomach, MCCG is able to detect superficial gastric neoplasms.     

Diagnosis of early gastric cancer using narrow band imaging and acetic acid

AIM: To determine whether the endoscopic findings of depressed-type early gastric cancers(EGCs) could precisely predict the histological type.METHODS: Ninety depressed-type EGCs in 72 patients were macroscopically and histologically identified. We evaluated the microvascular(MV) and mucosal surface(MS) patterns of depressed-type EGCs using magnifying endoscopy(ME) with narrow-band imaging(NBI)(NBI-ME) and ME enhanced by 1.5% acetic acid, respectively. First, depressed-type EGCs were classified according to MV pattern by NBI-ME. Subsequently, EGCs unclassified by MV pattern were classified according to MS pattern by enhanced ME(EME) images obtained from the same angle.RESULTS: We classified the depressed-type EGCs into the following 2 MV patterns using NBI-ME: a fine-network pattern that indicated differentiated adenocarcinoma(25/25, 100%) and a corkscrew pattern that likely indicated undifferentiated adenocarcinoma(18/23, 78.3%). However, 42 of the 90(46.7%) lesions could not be classified into MV patterns by NBI-ME. These unclassified lesions were then evaluated for MS patterns using EME, which classified 33(81.0%) lesions as MS patterns, diagnosed as differentiated adenocarcinoma. As a result, 76 of the 90(84.4%) lesions were matched with histological diagnoses using a combination of NBI-ME and EME.CONCLUSION: A combination of NBI-ME and EME was useful in predicting the histological type of depressedtype EGC.     

Detectability of colorectal neoplastic lesions using a narrow‐band imaging system: A pilot study

Background and Aim: Flat and depressed colorectal neoplastic lesions can be difficult to identify using conventional colonoscopy techniques. Narrow‐band imaging (NBI) provides unique views especially of mucosal vascular network and helps in visualization of neoplasia by improving contrast. The aim of this study was to assess the feasibility of using NBI for colorectal neoplasia screening. Methods: Forty‐seven consecutive patients, who underwent high definition colonoscopy (HDC) screening examinations revealing neoplastic lesions, were enrolled in our prospective study. No biopsies or resections were performed during the initial HDC, but patients in whom lesions were detected underwent further colonoscopies using NBI, with the results of the first examination blinded from the colonoscopist. They then received appropriate treatment. We compared diagnostic detection rates of neoplastic lesions for HDC and NBI procedures using total number of all identified neoplastic lesions as reference standard. Results: Altogether, 153 lesions were detected and analyzed in 43 patients. Mean diagnostic extubation times were not significantly different (P = 0.18), but the total number of lesions detected by NBI was higher (134 vs 116; P = 0.02). Based on macroscopic type, flat lesions were identified more often by NBI (P = 0.04). As for lesion size, only flat lesions < 5 mm were detected more frequently (P = 0.046). Lesions in the right colon were identified more often by NBI (P = 0.02), but NBI missed two flat lesions ≥ 10 mm located there. Conclusions: Narrow band imaging colonoscopy may represent a significant improvement in the detection of flat and diminutive lesions, but a future multi‐center controlled trial should be conducted to fully evaluate efficacy for screening colonoscopies.     

PIT PATTERN DIAGNOSIS FOR COLORECTAL NEOPLASIA USING NARROW BAND IMAGING MAGNIFICATION

Narrow band imaging (NBI) is a newly developed technology that uses optical filters for RGB sequential illumination and narrows the bandwidth of spectral transmittance. NBI enables the observation of the fine capillaries in the superficial mucosa of the gastrointestinal tract. In this report, the authors assessed the clinical usefulness of NBI magnification in pit pattern diagnosis for colorectal neoplasia. A total of 90 colorectal lesions including nine cases of hyperplasia, 60 of tubular adenoma and 21 of early carcinoma were analyzed. Histologic diagnosis was undertaken according to World Health Organization classifications. Magnified observation of the lesions was performed using NBI without chromoendoscopy, and pit pattern diagnosis was then recorded. After endoscopic or surgical resection of the lesion, the authors performed stereoscopic examination to confirm the pit pattern. From these data, the authors estimated the ability to diagnose pit patterns using NBI magnification without chromoendoscopy. The correspondence rate of pit pattern diagnosis between NBI magnification without chromoendoscopy and stereoscopic findings was 100% (9/9) for type II, 100% (56/56) for type IIIl , 100% (3/3) for type IV, 80% (12/15) for type Vi , and 57% (4/7) for type Vn . NBI magnification without chromoendoscopy demonstrated good results for pit pattern diagnosis of colorectal neoplasia, especially for lesions with regular pit pattern.     

PROSPECTIVE STUDY OF THE EVALUATION OF THE USEFULNESS OF TUMOR TYPING BY NARROW BAND IMAGING FOR THE DIFFERENTIAL DIAGNOSIS OF GASTRIC ADENOMA AND WELL‐DIFFERENTIATED ADENOCARCINOMA

Background and Aim: Presently, the differential diagnosis of gastric adenoma and well‐differentiated adenocarcinoma by endoscopy is very difficult. We carried out magnifying endoscopy with narrow band imaging (NBI) in lesions that required discrimination between gastric adenoma and well‐differentiated adenocarcinoma, and prospectively evaluated whether the tumor typing that we propose is useful for their differential diagnosis. Methods: The materials were 93 lesions that required differential diagnosis between gastric adenoma and well‐differentiated adenocarcinoma among the gastric epithelial tumors for which endoscopic treatment was planned at three facilities during the 14 months between November 2008 and December 2009. According to the typing method proposed by our facility based on images of the mucosal ultrastructure and microvessels obtained by magnified endoscopy combined with NBI, type I‐II and type III‐V lesions were diagnosed as gastric adenoma and well‐differentiated adenocarcinoma, respectively, before endoscopic treatment, and the accuracy of the diagnoses were prospectively examined by comparing them with the postoperative pathological findings. Results: Of the 93 lesions, 87 could be typed into the five types of our typing method, but six lesions could not be classified. The 87 lesions consisted of 16 type I, 12 type II, 29 type III, 27 type IV, and three type V lesions. The percentages of accurate preoperative diagnoses of types I‐II as adenoma and types III‐V as well‐differentiated adenocarcinoma were 79% and 93%, respectively. Conclusions: The tumor typing based on NBI was useful for the endoscopic differentiation of gastric adenoma and well‐differentiated adenocarcinoma.