The usefulness of magnifying endoscopy with narrow-band imaging to distinguish carcinoma in flat elevated lesions in the stomach diagnosed as adenoma by using biopsy samples

Histopathologic Diagnosis Discrepancies Between Preoperative Endoscopic Forceps Biopsies and Specimens Resected by Endoscopic Submucosal Dissection in Superficial Gastric Neoplasms

BACKGROUND

The standard of practice when a superficial lesion was identified during upper GI endoscopy is to take an endoscopic forceps biopsy (EFB) of the lesion. The histopathologic findings then will determine the management plan. Endoscopic submucosal dissection (ESD) enables en-bloc resection for early neoplasms of the gastrointestinal tract and provides an adequate specimen that permits a more reliable histopathologic assessment. The objective of this study was to determine the rate of histopathologic discrepancy between EFB and specimens resected by ESD, and to identify the predisposing risk factors for this discordance.

MATERIALS AND METHODS

This is a retrospective study, enrolling patients with superficial gastric neoplasms that underwent EFB followed by ESD. We divided cases to concordant or discordant group according to the histopathologic diagnosis of EFB and ESD specimens. We also analyzed the features that may have influenced the occurrence of histopathologic discordance and the association between discordant samples of adenocarcinoma and neoplastic invasion to deeper layers.

RESULTS

A total of 115 gastric ESD procedures were performed with 84 patients meeting the inclusion criteria. Histopathologic discordance between EFB and ESD specimens were observed in 35.8% of cases (30/84 lesions). The univariant-bivariant analysis and multivariate logistic regression analysis showed that histologic discordance was closely related to the size of the lesions ( P =0.028).

CONCLUSION

Histopathologic discrepancy between EFB and ESD specimens may occur in approximately one-third of cases, particularly for lesions over 20 mm, which may lead to crucial delays in gastric cancer precise diagnosis and treatment.

Can magnifying endoscopy with narrow-band imaging discriminate between carcinomas and low grade adenomas in gastric superficial elevated lesions?

Background and study aims: The aim of this study was to investigate the capability of magnifying endoscopy with narrow-band imaging (ME-NBI) to discriminate between early carcinomas (EC) and low grade adenomas (LGA) in gastric superficial elevated epithelial neoplasias. Patients and methods: We investigated 100 consecutive cases of gastric superficial elevated epithelial neoplasias that were removed using endoscopic submucosal dissection. The pathological diagnostic criteria were based on the revised Vienna classification; category 4 (mucosal high grade neoplasia) and category 5 (submucosal invasion by carcinoma) lesions were diagnosed as EC, whereas category 3 (mucosal low grade neoplasia) lesions were diagnosed as LGA. The associations between the postoperative pathological diagnoses and the ME-NBI findings were analyzed, and included the shape, specification, and area of irregularity in the microvascular architecture (MV) and the microsurface structure (MS). Results: Seventy-nine EC and 21 LGA cases diagnosed postoperatively were evaluated retrospectively. The lesion size (median; range (mm)) was significantly larger in the EC group (14; 2 - 95) compared to the LGA group (5; 2 - 16) (P < 0.001). Wavy forms in the MV shapes (P = 0.031), extension in the MV specifications (P = 0.035), and area with MV irregularity (P = 0.001) were found to be statistically significant predictive findings for EC. Villous forms in the MS shapes (P = 0.026), enlargement in the MS specifications (P = 0.044), and area with MS irregularity (P = 0.021) were also found to be statistically significant predictive findings for EC. The rates of preoperative sensitivity, specificity, and diagnostic accuracy of ME-NBI for discriminating EC were 86.1 %, 38.9 %, and 75 %, respectively. Conclusions: The present study suggests that ME-NBI is useful for the differential diagnosis of EC and LGA in gastric superficial elevated epithelial neoplasias.

STUDY REGISTRATION

UMIN000012925.

Magnifying endoscopy simple diagnostic algorithm for early gastric cancer (MESDA-G)

Gastric cancer is the third leading cause of cancer death worldwide. Early detection and accurate diagnosis of mucosal cancer is desirable in order to achieve decreased mortality; cause-specific survival of patients with early gastric cancer is reported to exceed 95%. Endoscopy is the functional modality to detect early cancer; however, the procedure is not definitive when using conventional white-light imaging. In contrast, magnifying narrow-band imaging (M-NBI), a novel endoscopic technology, is a powerful tool for characterizing gastric mucosal lesions because it can visualize the microvascular architecture and microsurface structure. To date, many reports on the diagnosis of early gastric cancer by M-NBI, including multicenter prospective randomized studies conducted in Japan, have been published in peer-reviewed international journals. Based on these published data, we devised a proposal for a diagnostic strategy for gastric mucosal cancer using M-NBI to simplify the process of diagnosis and improve accuracy. Herein, we recommend a diagnostic algorithm for early gastric cancer using magnifying endoscopy.

A multicenter randomized comparison between high-definition white light endoscopy and narrow band imaging for detection of gastric lesions

OBJECTIVE

Narrow band imaging (NBI) is generally considered to be useful for lesion characterization, but not enhanced detection of gastric lesions, because of the dark endoscopic view. We tested whether the new generation of NBI (190-NBI or 290-NBI), which is twice as bright as the previous version, would improve detection of premalignant gastric lesions compared with high-definition white light endoscopy (HD-WLE).

PATIENTS AND METHODS

This was a multicenter prospective randomized study involving five tertiary institutions in the Asia-Pacific region. A total of 579 patients aged older than 50 years who underwent diagnostic upper gastrointestinal endoscopy were randomized to either HD-WLE or NBI. The outcome measurements were detection of intestinal metaplasia (IM), focal gastric lesions, and gastric cancers.

RESULTS

Focal gastric lesions were detected in 83/286 (29%) and 119/293 patients (40.6%) by HD-WLE and by NBI, respectively (P=0.003). IM was detected in 22/286 patients (7.7%) by HD-WLE and in 52/293 patients (17.7%) by NBI (P<0.001). Gastric cancer were found in 7/286 (2.4%) and 3/293 patients (1%) in HD-WLE and NBI groups, respectively (P=0.189).

CONCLUSION

NBI increased the detection rate of IM compared with HD-WLE.

In vivo gastric mucosal histopathology using endocytoscopy

AIM: To study the ability of endocytoscopy to identify normal gastric mucosa and to exclude Helicobacter pylori (H. pylori) infection.

METHODS: Endocytoscopic examination of the gastric corpus and antrum was performed in 70 consecutive patients. Target biopsy specimens were also obtained from the assessed region and multiple H. pylori tests were performed. The normal endocytoscopy patterns of the corpus and antrum were divided into the normal pit-dominant type (n-Pit) or the normal papilla-dominant type (n-Pap), respectively characterized as either regular pits with capillary networks or round, smooth papillary structures with spiral capillaries. On the other hand, normal mucosa was defined as mucosa not demonstrating histological abnormalities, including inflammation and atrophy.

RESULTS: The sensitivity and specificity of n-Pit for normal mucosa in the gastric corpus were 94.4% and 97.1%, respectively, whereas those of n-Pap for normal mucosa in the antrum were 92.0% and 86.7%, respectively. The positive predictive values of n-Pit and n-Pap for H. pylori-negative tissue were 88.6% and 93.1%, respectively, and their negative predictive values for H. pylori-negative tissues were 42.9% and 41.5%, respectively. The inter-observer agreement for determining n-Pit and n-Pap for normal mucosa were 0.857 and 0.769, respectively, which is considered reliable.

CONCLUSION: N-Pit and n-Pap, seen using EC, are considered useful predictors of normal mucosa and the absence of H. pylori infection.

Diagnostic efficacy of magnifying endoscopy with narrow-band imaging for gastric neoplasms: a meta-analysis

Background

Magnifying endoscopy with narrow-band imaging (ME-NBI) is a novel, image-enhanced endoscopic technique for differentiating gastrointestinal neoplasms and potentially enabling pathological diagnosis.

Objectives

The aim of this analysis was to assess the diagnostic performance of ME-NBI for gastric neoplasms.

Methods

We performed a systematic search of the PubMed, EMbase, Web of Science, and Cochrane Library databases for relevant studies. Meta-DiSc (version 1.4) and STATA (version 11.0) software were used for the data analysis. Random effects models were used to assess diagnostic efficacy. Heterogeneity was tested by the Q statistic and I² statistic. Meta-regression was used to analyze the sources of heterogeneity.

Results

A total of 10 studies, with 2151 lesions, were included. The pooled characteristics of these studies were as follows: sensitivity 0.85 (95% confidence interval [CI]: 0.81–0.89), specificity 0.96 (95% confidence interval [CI]: 0.95–0.97), and area under the curve (AUC) 0.9647. In the subgroup analysis, which compared the diagnostic efficacy of ME-NBI and white light imaging (WLI), the pooled sensitivity and specificity of ME-NBI were 0.87 (95% CI: 0.80–0.92) and 0.93 (95% CI: 0.90–0.95), respectively, and the area under the curve (AUC) was 0.9556. In contrast, the pooled sensitivity and specificity of WLI were 0.61 (95% CI: 0.53–0.69) and 0.65 (95% CI: 0.60–0.69), respectively, and the area under the curve (AUC) was 0.6772.

Conclusions

ME-NBI presents a high diagnostic value for gastric neoplasms and has a high specificity.

Magnifying endoscopy of gastric epithelial dysplasia based on the morphologic characteristics

AIM

To investigate the difference in magnifying endoscopic findings of gastric epithelial dysplasias (GEDs) according to the morphologic characteristics.

METHODS

This study included 46 GED lesions in 45 patients who underwent magnifying endoscopy using narrow band imaging (ME-NBI) before endoscopic resection. During ME-NBI, the microvascular and microsurface (MS) patterns and the presence of light blue crest (LBC) and white opaque substance were investigated. GEDs were categorized as adenomatous, foveolar, and hybrid types, and their mucin phenotype was evaluated.

RESULTS

Of the 46 lesions, 27 (59%) were categorized as adenomatous, 15 (32%) as hybrid, and the remaining 4 (9%) as foveolar. All adenomatous GEDs showed the round pit and/or tubular MS patterns, all foveolar GEDs showed the papillary pattern, and hybrid GEDs showed mixed patterns (P < 0.001). LBC was more frequently observed in adenomatous GEDs than in hybrid or foveolar GEDs (52%, 33%, 0%, respectively), although this difference was not significant (P = 0.127). The papillary MS pattern was associated with MUC5AC and MUC6 expression, and the round pit and/or tubular MS patterns were associated with CD10 expression.

CONCLUSION

The MS pattern in ME-NBI findings is useful for predicting the morphologic category and mucin phenotype of GEDs, and ME-NBI findings may guide decisions regarding GED treatment.

Assessment of gastric phenotypes using magnifying narrow-band imaging for differentiation of gastric carcinomas from adenomas

Background. Conventional white-light endoscopy and forceps biopsy are insufficient for definitive diagnosis of gastric adenoma. Immunohistochemical studies have reported an obvious phenotypic difference between adenomas and carcinomas. We investigated the utility of narrow-band imaging with magnifying endoscopy (NBI-ME) for mucin phenotypic assessment to differentiate carcinomas from adenomas. Methods. NBI-ME findings were classified into A, B, and AB types, which revealed papillary, tubular pits and groove microstructures, respectively. To investigate A-B classifications retrospectively, 137 patients (155 lesions) that were diagnosed pretherapeutically with adenoma or borderline lesions by biopsy were enrolled. The mucin phenotype was analyzed immunohistochemically in the first 60 lesions. Results. After endoscopic submucosal dissection, A type and AB type lesions were determined histologically as carcinoma (81/82, 99%). B type lesions were adenoma (29/73, 40%) and carcinoma (44/73, 60%). A or AB type correlated to histological carcinomas (sensitivity 65%, specificity 97%, and accuracy 71%). Mucin phenotypes were gastric or gastrointestinal in A type and AB type carcinomas (31/37, 84%) and intestinal in B type adenomas and carcinomas (21/23, 91%). Conclusions. NBI-ME has the advantage of the assessment of mucin phenotypes in gastric carcinomas and adenomas. The proposed A-B classification is useful, especially for differentiation of gastric or gastrointestinal carcinomas from adenomas.

A novel magnetic countertraction device for endoscopic submucosal dissection significantly reduces procedure time and minimizes technical difficulty

BACKGROUND AND STUDY AIMS

In endoscopic submucosal dissection (ESD), effective countertraction may overcome the current drawbacks of longer procedure times and increased technical demands. The objective of this study was to compare the efficacy of ESD using a novel magnetic countertraction device with that of the traditional technique.

METHODS

Each ESD was performed on simulated gastric lesions of 30 mm diameter created at five different locations. In total, 10 ESDs were performed using this novel device and 10 were performed by the standard technique.

RESULTS

The magnetic countertraction device allowed directional tissue manipulation and exposure of the submucosal space. The total procedure time was 605 ± 303.7 seconds in the countertraction group vs. 1082 ± 515.9 seconds in the control group (P = 0.021).

CONCLUSIONS

This study demonstrated that using a novel magnetic countertraction device during ESD is technically feasible and enables the operator to dynamically manipulate countertraction such that the submucosal layer is visualized directly. Use of this device significantly reduced procedure time compared with conventional ESD techniques.

Narrow band imaging: application for early-stage gastrointestinal neoplasia

Narrow-band imaging (NBI) is an imaging technique for endoscopy using optical filters to narrow the bandwidth of spectral transmittance. Through this narrow spectrum, NBI contrasts surface structure and microvascular architecture of various lesions. In this article we focus on the application of NBI for early-stage neoplasia in the esophagus, stomach and colon with a three-step strategy of endoscopic diagnosis: (i) the detection of abnormality; (ii) the differentiation between non-neoplasia and neoplasia; and (iii) staging for tumor extension and depth of invasion.

Narrow band imaging with magnification for the diagnosis of lesions in the upper gastrointestinal tract

Endoscopy plays an important role in the diagnosis and management of gastrointestinal (GI) tract disorders. Chromoendoscopy has proven to be superior to white light endoscopy for early detection of various GI lesions. This has however been fraught with problems. The use of color stains, time taken to achieve an effect and the learning curve associated with the technique has been some of the pitfalls. Narrow band imaging (NBI) particularly in combination with magnifying endoscopy may allow the endoscopist to accomplish a fairly accurate diagnosis with good histological correlation similar to results achieved with chromoendoscopy. Such enhanced detection of pre-malignant and early neoplastic lesions in the gastrointestinal tract should allow better targeting of biopsies and could ultimately prove to be cost effective. Various studies have been done demonstrating the utility of this novel technology. This article will review the impact of NBI in the diagnosis of upper gastrointestinal tract disorders.

Magnifying endoscopy with narrow-band imaging helps determine the management of gastric adenomas

BACKGROUND

There are no clear clinical criteria for the management of gastric lesions diagnosed as adenomas (Vienna classification category 3) by pre-treatment biopsy. In the present study, we examined the feasibility of magnifying endoscopy with narrow-band imaging (ME-NBI) in discriminating early gastric cancers (Vienna classification category 4 or 5) from adenomas in lesions diagnosed as adenomas by pre-treatment biopsy.

METHODS

This was a single-center cross-sectional retrospective study at a tertiary referral center. One hundred thirty-seven consecutive cases of gastric lesions diagnosed as adenomas in pre-treatment forceps biopsy were examined with conventional non-magnifying endoscopy under white light, non-magnifying chromoendoscopy, and ME-NBI. We investigated the association between the final pathological diagnoses (carcinoma or adenoma) and the following factors: lesion size (mm), color (red or white), macroscopic type (depressed or others), presence of ulceration, and positive ME-NBI finding. The presence of an irregular microvascular pattern or an irregular microsurface pattern with a demarcation line between the lesion and the surrounding area was regarded as a positive ME-NBI finding.

RESULTS

Lesion size was significantly larger in carcinomas than adenomas (P = 0.005). Depressed lesion (P = 0.011), red color (P < 0.001), and positive ME-NBI finding (P < 0.001) were significant predictive factors for carcinoma. Multivariate logistic regression confirmed that red color (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.26-7.34, P = 0.14) and a positive ME-NBI finding (OR 13.68, 95% CI 5.69-32.88, P < 0.001) were independent predictive factors for carcinomas. A positive ME-NBI finding was the strongest predictive factor.

CONCLUSIONS

ME-NBI is useful in planning the management of lesions diagnosed as adenomas by pre-treatment forceps biopsy.

Current clinical applications of magnifying endoscopy with narrow band imaging in the stomach

Narrow band imaging (NBI), in conjunction with magnifying endoscopy (ME), has arisen more and more attention in the area of advanced endoscopy. By enhancing the mucosal microvascular architecture and surface pattern, it is feasible to use ME-NBI to identify subtle changes associated with gastric inflammation, atrophy, intestinal metaplasia, and early gastric cancer. The new technique thus plays a valuable role in therapeutic decision-making, endoscopic treatment process, postoperative evaluation, and follow-up examination. To date, many criteria or evaluation method of ME-NBI has been proposed. This paper aims to summarize the various diagnosing classifications and the current clinical applications of ME-NBI in the stomach.

Diagnosis of gastric intraepithelial neoplasia by narrow-band imaging and confocal laser endomicroscopy

AIM: To evaluate the diagnosis of different differentiated gastric intraepithelial neoplasia (IN) by magnification endoscopy combined with narrow-band imaging (ME-NBI) and confocal laser endomicroscopy (CLE).

METHODS: Eligible patients with suspected gastric IN lesions previously diagnosed by endoscopy in secondary hospitals and scheduled for further diagnosis and treatment were recruited for this study. Excluded from the study were patients who had liver cirrhosis, impaired renal function, acute gastrointestinal (GI) bleeding, coagulopathy, esophageal varices, jaundice, and GI post-surgery. Also excluded were those who were pregnant, breastfeeding, were younger than 18 years old, or were unable to provide informed consent. All patients had all mucus and bile cleared from their stomachs. They then received upper GI endoscopy. When a mucosal lesion is found during observation with white-light imaging, the lesion is visualized using maximal magnification, employing gradual movement of the tip of the endoscope to bring the image into focus. Saved images are analyzed. Confocal images were evaluated by two endoscopists (Huang J and Li MY), who were familiar with CLE, blinded to the related information about the lesions, and asked to classify each lesion as either a low grade dysplasia (LGD) or high grade dysplasia (HGD) according to given criteria. The results were compared with the final histopathologic diagnosis. ME-NBI images were evaluated by two endoscopists (Lu ZS and Ling-Hu EQ) who were familiar with NBI, blinded to the related information about the lesions and CLE images, and were asked to classify each lesion as a LGD or HGD according to the “microvascular pattern and surface pattern” classification system. The results were compared with the final histopathologic diagnosis.

RESULTS: The study included 32 pathology-proven low grade gastric IN and 26 pathology-proven high grade gastric IN that were detected with any of the modalities. CLE and ME-NBI enabled clear visualization of the vascular microsurface patterns and microvascular structures of the gastric mucosa. The accuracy of the CLE and the ME-NBI diagnosis was 88% (95% CI: 78%-98%) and 81% (95% CI: 69%-93%), respectively. The kappa coefficient of agreement between the histopathology and the in vivo CLE imaging was 0.755; between the histopathology and the in vivo CLE imaging was 0.615. McNemar’s test (binomial distribution used) indicated that the agreement was significant (P < 0.05). When patients were diagnosed by ME-NBI with CLE, the overall accuracy of the diagnosis was 86.21% (95% CI: 73%-96%), and the kappa coefficient of agreement was 0.713, according to McNemar’s test (P < 0.05).

CONCLUSION: Higher diagnostic accuracy, sensitivity and specificity of CLE over ME-NBI indicate the feasibility of these two techniques for the efficacious diagnostic classification of gastric IN.

The diagnostic utility of narrow band imaging magnifying endoscopy in clinical practice in a population with intermediate gastric cancer risk

OBJECTIVE

Narrow band imaging (NBI) and NBI-magnifying endoscopy (ME) have been reported to facilitate the diagnosis of intestinal metaplasia (IM) and early gastric cancer (EGC) in high-risk populations. This study aimed at comparing the detection rate of focal gastric lesions by NBI against white light endoscopy (WLE), and examined the utility of NBI-ME in differentiating gastric mucosal pathology in a population with intermediate gastric cancer risk.

METHODS

Chinese patients aged 35-70 years undergoing diagnostic gastroscopy (GIF FQ260Z) by six experienced endoscopists were enrolled prospectively. The sequence of endoscopic evaluation was WLE followed by NBI. Focal lesions were re-examined by NBI-ME. The incremental diagnostic yield of NBI over WLE and ability of NBI-ME to differentiate gastric mucosal pathology were analyzed.

RESULTS

Over a 30-month period, 458 patients (mean age: 52 years; men: 53.7%; Helicobacter pylori positive: 20.1%) were recruited. WLE detected a focal gastric lesion in 43.7% (200/458). WLE made a definitive diagnosis in 148 out of 200 patients (147 benign lesions and one gastric cancer), whereas NBI-ME correctly clarified the nature of the remaining 52 lesions (benign: 51; EGC: one). NBI detected an additional 69 out of 458 lesions (type 0_IIa: 91.3%; type 0_IIb: 8.7%) missed by WLE; the diagnoses based on NBI-ME were IM (67/69), EGC (1/69), and benign lesion (1/69). Interobserver agreement study revealed a κ statistic of 0.71.

CONCLUSION

NBI detected IM missed by WLE. NBI-ME was useful in differentiating the pathology of focal gastric mucosal lesions.

An update in endoscopic management of gastric cancer

PURPOSE OF REVIEW

Gastric cancer remains a prevalent disease with a 5-year mortality rate of less than 25%. This review focuses on the endoscopic detection, staging, and management of gastric adenocarcinoma.

RECENT FINDINGS

Confocal laser endomicroscopy and narrow band imaging have a 77-99.4% sensitivity for early cancer detection, a significant improvement when compared with white light endoscopy. Proper staging can be accomplished through endoscopic ultrasound and multidetector row-computed tomography, with accuracy as high as 90.1%. Endoscopic management of early gastric cancer is minimally invasive and can be preferable to surgery. In properly selected patients, endoscopic submucosal dissection has been found to have 100% 5-year survival.

SUMMARY

The recent advances in gastric cancer have greatly improved the care we can offer our patients in gastric oncology. The emerging technologies will hopefully continue to promote this trend.

Usefulness of transnasal endoscopy where endoscopic submucosal dissection is difficult

BACKGROUND

Early gastric cancer located from the pyloric ring to inside the duodenal bulb (DB) is not easily treated by endoscopic submucosal dissection (ESD). The endoscope needs to be reversed inside the DB to set the resection line at a safe distance from the anal side. Because of the space limitations and limited flexibility of conventional endoscopy (CE), there have been increasing possibilities of complications. Here we report a new ESD technique using a transnasal endoscope (TN-E) that is reversed inside the DB.

METHODS

The subjects were 5 patients with early gastric cancer or adenoma, at locations ranging from the pyloric ring to inside the DB, who were all treated by ESD. We compared results in these patients (TN-E group) with results in five patients with similar disease characteristics who were treated by ESD before July 2008, when the TN-E treatment method was introduced (CE group). In the TN-E group, after marking by CE, we switched the endoscope to the TN-E, and performed the reversing procedure inside the DB, and cut the anal side of the lesion in a semicircle. We switched back to CE to dissect the remaining half on the oral side. We compared the average resection time, en-bloc resection rate, and safety margin between the TN-E and CE groups.

RESULTS

Reversing inside the DB and the anal-side procedures proved easy and there were no complications. No bleeding or perforation occurred. The average resection times and en-bloc resection rates were not different between the two groups. All the resections by the TN-E were more than 5 mm away from the tumor margin, whereas a resection rate with a safety margin of more than 5 mm was 80% by CE.

CONCLUSIONS

In conclusion, the TN-E was safe and effective for use inside the DB. ESD using the TN-E contributed to accurate pathological diagnosis, because the size of the resected specimen was sufficient to prevent the burning effect caused by the ESD.