Mucin phenotype and narrow-band imaging with magnifying endoscopy for differentiated-type mucosal gastric cancer

Mucin phenotype and microvessels in early gastic cancer: Magnifying endoscopy with narrow band imaging

Backgrounds

In order to detect early gastric cancer (EGC), this research sought to assess the diagnostic utility of magnifying endoscopy (ME) as well as the significance of mucin phenotype and microvessel features.

Methods

402 individuals with an EGC diagnosis underwent endoscopic submucosal dissection (ESD) at the Department of ME between 2012 and 2020. After adjusting for image distortion, high-magnification endoscopic pictures were taken and examined to find microvessels in the area of interest. The microvessel density was measured as counts per square millimeter (counts/mm2) after segmentation, and the vascular bed's size was computed as a percentage of the area of interest. To identify certain properties of the microvessels, such as end-points, crossing points, branching sites, and connection points, further processing was done using skeletonized pixels.

Results

According to the research, undifferentiated tumors often lacked the MS pattern and showed an oval and tubular microsurface (MS) pattern, but differentiated EGC tumors usually lacked the MS pattern and presented a corkscrew MV pattern. Submucosal invasion was shown to be more strongly associated with the destructive MS pattern in differentiated tumors as opposed to undifferentiated tumors. While lesions with a corkscrew MV pattern and an antrum or body MS pattern revealed greater MUC5AC expression, lesions with a loop MV pattern indicated higher MUC2 expression. Furthermore, CD10 expression was higher in lesions with a papillary pattern and an antrum or body MS pattern.

Conclusion

These results imply that evaluating mucin phenotype and microvessel features in conjunction with magnifying endoscopy (ME) may be a useful diagnostic strategy for early gastric cancer (EGC) detection. Nevertheless, further investigation is required to confirm these findings and identify the best course of action for EGC diagnosis.

Endoscopic Diagnosis of Epithelial Subtypes of Superficial Non-Ampullary Duodenal Epithelial Tumors using Magnifying Narrow-Band Imaging

INTRODUCTION

Superficial non-ampullary duodenal epithelial tumors (SNADETs) include low-grade adenoma (LGA) and high-grade adenoma or carcinoma (HGA/Ca) and are classified into two different epithelial subtypes, gastric-type (G-type) and intestinal-type (I-type). We attempted to distinguish them by endoscopic characteristics including magnifying endoscopy with narrow-band imaging (M-NBI).

METHODS

Various endoscopic and M-NBI findings of 286 SNADETs were retrospectively reviewed and compared between G- and I-types and histological grades. M-NBI findings were divided into four patterns based on the following vascular patterns; absent, network, intrastructural vascular (ISV), and unclassified. Lesions displaying a single pattern were classified as mono-pattern and those displaying multiple patterns as mixed-pattern. Lesions showing CDX2 positivity were categorized as I-types and those showing MUC5AC or MUC6 positivity were categorized as G-types based on immunohistochemistry.

RESULTS

Among 286 lesions, 23 (8%) were G-type and 243 (85%) were I-type. More G-type lesions were located oral to papilla (91.3 vs. 45.6%, p < 0.001), and had protruding morphology compared to those of I-types (65.2 vs. 14.4%, p < 0.001). The major M-NBI pattern was ISV in G-type (78.2 vs. 26.3%, p < 0.001), and absent for I-type (0 vs. 34.5%, p = 0.003). Three endoscopic characteristics; location oral to papilla, protruding morphology, and major M-NBI pattern (ISV) were independent predictors for G-type. Mixed-pattern was more common in HGA/Ca than LGA for I-type (77.0 vs. 58.8%, p = 0.01); however, there was no difference for those in G-type.

CONCLUSION

Endoscopic findings including M-NBI are useful to differentiate epithelial subtypes.

Comparison of clinical and pathological features between early-stage gastric-type and intestinal-type differentiated adenocarcinoma: a retrospective study

BACKGROUND

The clinicopathological features and endoscopic characteristics under magnifying endoscopy with narrow band imaging (ME-NBI) between early-stage gastric-type differentiated adenocarcinoma (GDA) and intestinal-type differentiated adenocarcinoma (IDA) remain controversial.

METHODS

Early gastric adenocarcinomas that underwent endoscopic submucosal dissection (ESD) in Nanjing Drum Tower Hospital between August 2017 and August 2021 were included in the present study. GDA cases and IDA cases were selected based on morphology and immunohistochemistry staining of CD10, MUC2, MUC5AC, and MUC6. Clinicopathological data and endoscopic findings in ME-NBI were compared between GDAs and IDAs.

RESULTS

The mucin phenotypes of 657 gastric cancers were gastric (n = 307), intestinal (n = 109), mixed (n = 181) and unclassified (n = 60). No significant difference was observed in terms of gender, age, tumor size, gross type, tumor location, background mucosa, lymphatic invasion, and vascular invasion between patients with GDA and IDA. GDA cases were associated with deeper invasion than IDA cases (p = 0.007). In ME-NBI, GDAs were more likely to exhibit an intralobular loop patten, whereas IDAs were more likely to exhibit a fine network pattern. In addition, the proportion of none-curative resection in GDAs was significantly higher than that in IDAs (p = 0.007).

CONCLUSION

The mucin phenotype of differentiated early gastric adenocarcinoma has clinical significance. GDA was associated with less endoscopically resectability than IDA.

Association between mucin phenotype and lesion border detection using acetic acid-indigo carmine chromoendoscopy in early gastric cancers

BACKGROUND

For successful treatment of early gastric cancers (EGCs), it is crucial to define the horizontal border of the lesion with high accuracy. Acetic acid-indigo carmine (AI) chromoendoscopy has been used to determine the horizontal border in EGCs, but this technique is less potent in certain situations. Mucin phenotype in gastric cancers refers to biological differences in precursor lesions and differences in histopathologic findings, and it might affect AI chromoendoscopy findings. We aimed to investigate the association between mucin phenotype and AI chromoendoscopy findings in EGCs.

METHODS

We prospectively evaluated 126 lesions in 126 patients with endoscopically diagnosed EGCs. Conventional endoscopy and AI chromoendoscopy findings of these lesions before treatment were prospectively analyzed. The border distinction between the lesion and surrounding mucosa was classified as distinct or indistinct on conventional endoscopy and AI chromoendoscopy, respectively. Mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null type by immunohistochemistry.

RESULTS

The lesion borders were distinct in 46.8% (59/126) of the lesions assessed using conventional endoscopy and in 73.0% (92/126) of those assessed with AI chromoendoscopy (p < 0.001). The border distinction rate of differentiated-type cancers on AI chromoendoscopy was significantly higher than that on conventional endoscopy (66/71 [93.0%] vs. 34/71 [47.9%], p < 0.001), but the border distinction rate of undifferentiated-type cancers on AI chromoendoscopy was not different from that on conventional endoscopy (26/55 [47.3%] vs. 25/55 [45.5%], p = 0.848). Compared with conventional endoscopy, AI chromoendoscopy identified borders in a significantly higher percentage of gastric, intestinal, and gastrointestinal mucin types; however, there was no difference in AI chromoendoscopy findings according to the mucin phenotype (p = 0.271).

CONCLUSION

AI chromoendoscopy was effective in horizontal border delineation in differentiated-type EGCs, but not in undifferentiated-type EGCs. Mucin phenotype had no effect on border distinction using AI chromoendoscopy.

The mucin phenotype does not affect the endoscopic resection outcome of non-ampullary duodenal epithelial tumors

Background and study aims  Some studies have reported an association between clinicopathological features and mucin phenotypes of non-ampullary duodenal epithelial tumors (NADETs). However, the association between clinical outcomes of endoscopic resection (ER) and mucin phenotypes has not been elucidated. The aim of this retrospective study was to analyze clinical outcomes of ER of NADETs with reference to mucin phenotypes. Patients and methods  We retrospectively evaluated the clinical outcomes of ER for NADETs performed from 2006 to 2019 and compared clinicopathological characteristics, ER procedures, and outcomes, including adverse events (AEs) among tumors classified by mucin phenotype. Mucin phenotypes were classified as gastric, gastrointestinal, and intestinal based on immunohistochemical examination. Grade of dysplasia was determined according to the Vienna classification (VCL). Results  The proportion of VCL 4/5 was higher in the gastric type (50 %) compared with that in the gastrointestinal (39.1 %, P  = 0.009) and intestinal types (5.4 %, P  = 0.008), respectively. With no statistical difference in tumor size and ER method among the three groups, no significant difference was observed for ER outcomes, i. e., en bloc and R0 resection rates. In the gastrointestinal and intestinal types, AEs occurred in four cases treated with ESD, but none developed in the gastric type. Conclusions  This study suggests that the mucin phenotype does not affect resection outcome. However, considering high malignant potential and tendency for low AE rates, the gastric type NADETs may be more appropriate for proactive ER than the others.

Application of Current Image-Enhanced Endoscopy in Gastric Diseases

Image-enhanced endoscopy (IEE) plays an integral role in endoscopic diagnosis and treatment. IEE enables an early and accurate detection of cancer and characterization of lesions prior to therapeutic decisions. Ideal IEE can serve as an optical or digital chromoscopic endoscopy, as well as an optical biopsy that predicts exact histopathology. Several IEE modalities have recently been developed and are used in the clinical field. The stomach is a challenging organ for imaging because of its complex secretion function and status of Helicobacter pylori infection. Therefore, understanding the current IEE modalities for their clinical applicability in an evidence-based approach is warranted. Along with technology refinements, the new paradigm will be available for the diagnosis of gastric cancer or other conditions in the stomach in the near future.

Histological Architecture of Gastric Epithelial Neoplasias That Showed Absent Microsurface Patterns, Visualized by Magnifying Endoscopy with Narrow-Band Imaging

BACKGROUND/AIMS

The objective of this study was to elucidate the histological structure of the absent microsurface patterns (MSPs) that were visualized by magnifying endoscopy with narrow-band imaging (M-NBI).

METHODS

The study included consecutive gastric epithelial neoplasias for which M-NBI findings and histological findings could be compared on a one-to-one basis. The lesions were classified as absent MSPs and present MSPs based on the findings obtained using M-NBI. Of the histopathological findings for each lesion that corresponded to M-NBI findings, crypt opening densities, crypt lengths, crypt opening diameters, intercrypt distances, and crypt angles were measured and compared.

RESULTS

Thirty-six lesions were included in the analysis; of these, 17 lesions exhibited absent MSP and 19 lesions exhibited present MSP. Comparing the histological measurements for absent MSPs vs. present MSPs, median crypt opening density was 0.9 crypt openings/mm vs. 4.8 crypt openings/mm (p<0.001), respectively. The median crypt length, median crypt opening diameter, median intercrypt distance, and median crypt angle were 80.0 μm vs. 160 μm (p<0.001), 40.0 μm vs. 44.2 μm (p=0.09), 572.5 μm vs. 166.7 μm (p<0.001), and 21.6 degrees vs. 15.5 degrees (p<0.001), respectively.

CONCLUSION

Histological findings showed that lesions exhibiting absent MSPs had lower crypt opening density, shorter crypt length, greater intercrypt distance, and larger crypt angle.

Diagnostic algorithm of magnifying endoscopy with crystal violet staining for non-ampullary duodenal epithelial tumors

OBJECTIVES

Little is known about the usefulness of magnifying endoscopy with crystal violet staining (ME-CV) for the diagnosis of duodenal tumors. We assessed the ability of ME-CV to distinguish Vienna classification (VCL) category 4/5 (C4/5) from category 3 (C3) non-ampullary duodenal epithelial tumors (NADETs).

METHODS

A total of 76 NADETs were studied. We retrospectively analyzed the diagnostic values of the white light endoscopy (WLE) scoring system and the ME-CV algorithm with receiver operating characteristic (ROC) curves, and three endoscopists calculated the sensitivity, specificity, accuracy, and the area under the curve (AUC) of each. The diagnostic values were tested among NADETs overall and among subgroups of tumors with gastric, gastrointestinal or intestinal mucin phenotypes. Inter-observer agreement of the diagnostic results was also calculated.

RESULTS

According to the VCL, 54 lesions (71.1%) were regarded as C3 and 22 lesions (28.9%) as C4/5. The sensitivity, specificity, accuracy and AUC of ME-CV were higher than those of the WLE scoring system (63.6 vs 54.5, 85.2 vs 75.9, 78.9 vs 69.7, 0.744 vs 0.652, respectively). Inter-observer agreements of the WLE scoring system and ME-CV were both moderate (kappa 0.45 and 0.41). ME-CV had higher sensitivity, specificity, accuracy and AUC than those of the WLE scoring system among the gastric and intestinal phenotypes of NADETs.

CONCLUSIONS

ME-CV is appropriate for the diagnosis of C4/5 and C3 NADETs.

Differentiation between duodenal neoplasms and non-neoplasms using magnifying narrow-band imaging - Do we still need biopsies for duodenal lesions?

OBJECTIVES

Endoscopic biopsies for nonampullary duodenal epithelial neoplasms (NADENs) can induce submucosal fibrosis, making endoscopic resection difficult. However, no biopsy-free method exists to distinguish between NADENs and non-neoplasms. We developed a diagnostic algorithm for duodenal neoplasms based on magnifying endoscopy findings and evaluated the model's diagnostic ability.

METHODS

Magnified endoscopic images and duodenal lesion histology were collected consecutively between January 2015 and April 2016. Diagnosticians classified the surface patterns as pit, groove or absent. In cases of nonvisible surface patterns, the vascular pattern was evaluated to determine regularity or irregularity. The correlation between our algorithm (pit-type or absent with irregular vascular pattern) and the lesion histology were evaluated. Four evaluators, who were blinded to the histology, also classified the endoscopic findings and evaluated the diagnostic performance and interobserver agreement.

RESULTS

Endoscopic images of 114 lesions were evaluated (70 NADENs and 44 non-neoplasms, 31 in the superior and 83 in the descending and horizontal duodenum). Of the NADEN surface patterns, 88% (62/70) were pit-type, while 79% (35/44) of the non-neoplasm surface patterns were groove-type. Our diagnostic algorithm for differentiating NADENs from non-neoplasms was high (sensitivity 96%, specificity 95%) in the descending and horizontal duodenum. The evaluators' diagnostic performances were also high, and interobserver agreement for the algorithm was good between each diagnostician and evaluator (κ = 0.60-0.76).

CONCLUSION

Diagnostic performance of our algorithm sufficiently enabled eliminating endoscopic biopsies for diagnosing the descending and horizontal duodenum.

Clinicopathological Features and Magnifying Chromoendoscopic Findings of Non-Ampullary Duodenal Epithelial Tumors

BACKGROUND AND AIMS

We aimed to investigate an association between clinicopathological features, including immunohistochemical mucin phenotypes, and magnifying chromoendoscopic findings with crystal violet staining (ME-CV) in non-ampullary duodenal epithelial tumors (NADETs).

METHODS

A total of 55 patients with NADET were divided into 3 groups by mucin phenotype: intestinal, gastrointestinal, or gastric. ME-CV findings were classified into 4 patterns: convoluted, leaf-like, reticular/sulciolar, and pinecone. The clinicopathological features and ME-CV findings were compared among the mucin phenotypes.

RESULTS

Tumors of the gastric type were located in the duodenal bulb (p < 0.001), and contained pyloric gland adenoma (p < 0.001) more frequently than the other types. White-light endoscopy indicated that milk-white mucosa was less frequent in tumors of the gastric type than in those of the gastrointestinal type (p = 0.006) and the intestinal type (p < 0.001). ME-CV findings were significantly different between the gastric type and the other type (p = 0.028). Totally, 5 of 8 tumors of the gastric type manifested a pinecone pattern, 4 of which were compatible with pyloric gland adenoma.

CONCLUSIONS

The endoscopic findings of NADETs differ according to mucin phenotype. A pinecone pattern under ME-CV may be characteristic of NADETs of the gastric type, especially pyloric gland adenoma.

Endoluminal Diagnosis of Early Gastric Cancer and Its Precursors: Bridging the Gap Between Endoscopy and Pathology

Although dye-based and image-enhanced endoscopic techniques have revolutionized endoscopic diagnosis, conventional white light endoscopy still plays an important role in the diagnosis of early gastric cancer (EGC) during routine endoscopy. Chromoendoscopy reveals morphological characteristics of the mucosal lesions by enhancing mucosal contrast, while narrow-band imaging (NBI) facilitates detailed evaluation of the vascular architecture and surface features. Positive diagnostic findings of EGC on white light imaging and indigo carmine chromoendoscopy are a sharply demarcated lesion and irregularity in surface morphology or color. Magnifying NBI further improves diagnostic accuracy of white light imaging and chromoendoscopy. We review our approach to the endoscopic diagnosis of (pre-)malignant lesions in the stomach and discuss in detail novel endoscopic microvascular architectural patterns which further leverage diagnostic biopsy yield. We expect that further improvement of endoscopic techniques and correlative studies will close the gap between endoscopy and pathology.

Magnifying Endoscopy with Narrow Band Imaging of Early Gastric Cancer: Correlation with Histopathology and Mucin Phenotype

BACKGROUND/AIMS

Magnifying endoscopy with narrow band imaging (ME-NBI) is a useful modality for the detailed visualization of microsurface (MS) and microvascular (MV) structures in the gastrointestinal tract. This study aimed to determine whether the MS and MV patterns in ME-NBI differ according to the histologic type, invasion depth, and mucin phenotype of early gastric cancers (EGCs).

METHODS

The MS and MV patterns of 160 lesions in 160 patients with EGC who underwent ME-NBI before endoscopic or surgical resection were prospectively collected and analyzed. EGCs were categorized as either differentiated or undifferentiated and as either mucosal or submucosal, and their mucin phenotypes were determined via immunohistochemistry of the tumor specimens.

RESULTS

Differentiated tumors mainly displayed an oval and/or tubular MS pattern and a fine network or loop MV pattern, whereas undifferentiated tumors mainly displayed an absent MS pattern and a corkscrew MV pattern. The destructive MS pattern was associated with submucosal invasion, and this association was more prominent in the differentiated tumors than in the undifferentiated tumors. MUC5AC expression was increased in lesions with either a papillary or absent MS pattern and a corkscrew MV pattern, whereas MUC6 expression was increased in lesions with a papillary MS pattern and a loop MV pattern. CD10 expression was more frequent in lesions with a fine network MV pattern.

CONCLUSIONS

ME-NBI can be useful for predicting the histopathology and mucin phenotype of EGCs.

Therapeutic or spontaneous Helicobacter pylori eradication can obscure magnifying narrow-band imaging of gastric tumors

BACKGROUND AND STUDY AIMS

We previously reported that narrow-band imaging with magnifying endoscopy (NBI-ME) revealed a unique "gastritis-like" appearance in approximately 40 % of early gastric cancers after Helicobacter pylori eradication. Because rates of gastric cancer are increasing in patients with non-persistent infection of H. pylori, we aimed to clarify contribution factors to obscure tumors after therapeutic or spontaneous eradication.

PATIENTS AND METHODS

NBI-ME findings were examined retrospectively in 194 differentiated-type adenocarcinomas from H. pylori-negative patients with prior eradication therapy (83 patients) or without prior eradication therapy (72 patients). A gastritis-like appearance under NBI-ME was defined as an orderly microsurface structure and/or loss of clear demarcation with resemblance to the adjacent, non-cancerous mucosa. The correlation of this phenomenon with the degree of atrophic gastritis, determined both histologically in the adjacent mucosa and endoscopically, was evaluated.

RESULTS

The tumor-obscuring gastritis-like appearance was observed in 42 % and 23 % of the patients in the H. pylori eradication and non-eradication groups, respectively. The development of this appearance was affected by the histological grade of atrophy (P = 0.003) and intestinal metaplasia (P < 0.001) on univariate analysis. Multivariate analysis revealed an odds ratio of 0.25 (95 % confidence interval 0.10 - 0.61, P = 0.002) for an endoscopically severe extent of atrophy, independently of eradication therapy.

CONCLUSIONS

An endoscopically mild or moderate extent of atrophy is associated with a gastritis-like appearance under NBI-ME in currently H. pylori-negative gastric cancers. Surveillance endoscopy should be performed carefully after successful eradication or spontaneous elimination of H. pylori, particularly in patients with non-severe atrophic background mucosa.

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.

Histologic differentiation and mucin phenotype in white opaque substance-positive gastric neoplasias

BACKGROUND AND STUDY AIMS

The authors previously reported that the white opaque substance (WOS) in gastric epithelial neoplasia was caused by accumulation of lipid droplets by immunohistochemical and immunoelectron microscopic studies of adipophilin, which was recently identified and validated as a marker of lipid droplets. The aim of the current study was to investigate the characteristics of the histologic differentiation and mucin phenotype in WOS-positive gastric epithelial neoplasias.

PATIENTS AND METHODS

A total of 130 gastric epithelial neoplasias (45 adenomas and 85 early adenocarcinomas) from 120 patients were retrospectively evaluated. The presence or absence of WOS was evaluated by M-NBI. Lipids were examined by immunohistochemical staining for adipophilin. Tissue phenotypes were immunohistochemically classified as intestinal (I), gastrointestinal (GI), and gastric (G) using antibodies against CD10, MUC2, MUC5AC and MUC6. The histologic differentiation and mucin phenotype of WOS-positive neoplasias were characterized and examined according to adipophilin expression.

RESULTS

The presence of WOS by M-NBI was correlated with histologic differences between adenoma or differentiated type adenocarcinoma and mixed type or undifferentiated type adenocarcinoma (P = 0.0153). Adipophilin was only expressed in primary adenoma and well to moderately differentiated adenocarcinoma components but not in undifferentiated components. WOS and adipophilin expression were only observed in neoplasias with I or GI phenotypes, but not in those with the G phenotype (P < 0.0001).

CONCLUSIONS

WOS in gastric epithelial neoplasias might indicate differentiation into a mature histological subtype with GI or I mucin phenotype.

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.

Prediction of submucosal gastric cancer by narrow-band imaging magnifying endoscopy

BACKGROUND

The features of gastric submucosal cancer revealed by magnifying endoscopy have not been reported. Aim of our study was to investigate whether magnifying endoscopy could contribute to the diagnosis of submucosal invasion.

PATIENTS AND METHODS

In this prospective, cross-sectional study, 197 lesions of gastric differentiated adenocarcinoma, diagnosed as mucosal cancer by conventional endoscopy, were observed by magnifying endoscopy with narrow-band imaging, paying attention to the presence of a blurry mucosal pattern and an irregular mesh pattern. After endoscopic submucosal dissection, all lesions were examined histologically and the areas of two features were estimated.

RESULTS

Among the lesions examined, 177 were diagnosed histologically as mucosal cancer and 20 as submucosal cancer. Multivariate logistic regression analysis confirmed that a blurry mucosal pattern (odds ratio 12.15, 95% confidence interval 3.45-42.76, p=0.000) and an irregular mesh pattern (22.55, 4.22-120.45, p=0.000) were independent predictors of submucosal invasion.

CONCLUSIONS

Narrow band imaging magnifying endoscopic features are useful for predicting submucosal invasion in gastric cancer.

Magnifying narrow-band imaging of surface maturation in early differentiated-type gastric cancers after Helicobacter pylori eradication

BACKGROUND

Even after successful Helicobacter pylori eradication, primary or metachronous gastric cancers are sometimes discovered. The endoscopic features of these cancers may be modified by controlling inflammation. Characteristic findings for such lesions in terms of narrow-band imaging with magnifying endoscopy (NBI-ME) and histopathology need to be clarified to allow accurate diagnosis.

METHODS

Distinctive NBI-ME characteristics were examined retrospectively in intramucosal or minimally submucosal and differentiated-type adenocarcinomas from a successful eradication group (42 patients, 50 lesions) and a non-eradicated control group (44 patients, 50 lesions) matched in age and sex. A "gastritis-like" appearance under NBI-ME was characterized by uniform papillae and/or tubular pits with a whitish border, regular or faint microvessels and unclear demarcation, resembling the adjacent noncancerous mucosa. Histological differentiation at the luminal surface of the cancer was evaluated according to Ki-67 immunoreactivity restricted at the middle or lower portion of the tubules. NBI-ME alteration was prospectively confirmed in 29 patients (30 lesions) after eradication therapy.

RESULTS

The frequency of a "gastritis-like" appearance was 44% (22/50) for the eradication group, which was significantly higher than the 4% (2/50) for the control group (p < 0.001). In the eradication group, the "gastritis-like" appearance was significantly correlated with histological surface differentiation (p < 0.001). In the prospective study, NBI-ME showed changes to heterogeneous papillary microstructures in 43% (10/23) of the lesions after successful eradication at short-term follow-up.

CONCLUSIONS

Identification of surface maturation under NBI-ME offers a promising approach for accurate diagnosis of early gastric cancers after successful eradication.

Correlation between magnifying narrow-band imaging endoscopy results and organoid differentiation indicated by cancer cell differentiation and its distribution in depressed- type early gastric carcinoma

BACKGROUND

A close association between patterns identified by magnifying narrow-band imaging (M-NBI) and histological type has been described. M-NBI patterns were also recently reported to be related to the mucin phenotype; however, detials remain unclear.

MATERIALS AND METHODS

We investigated the cellular differentiation of gastric cancer lesions, along with their mucosal distribution observed by M-NBI. Ninety-seven depressed-type early gastric cancer lesions (74 differentiated and 23 undifferentiated adenocarcinomas) were visualized by M-NBI. Findings were divided into 4 patterns based on abnormal microvascular architecture: a chain loop pattern (CLP), a fine network pattern (FNP), a corkscrew pattern (CSP), and an unclassified pattern. Mucin phenotypes were judged as gastric (G-type), intestinal (I-type), mixed gastric and intestinal (M-type), and null (N-type) based on 4 markers (MAC5AC, MUC6, MUC2, and CD10). The relationship of each pattern of microvascular architecture with organoid differentiation indicated by cancer cell differentiation and its distribution in each histological type of early gastric cancer was investigated.

RESULTS

All CLP and FNP lesions were differentiated. The cancer cell distribution showed organoid differentiation in 84.2% (16/19) and 61.1% (22/36) of the two types of lesions, respectively, and there was a significant difference from the unclassified pattern with organoid differentiation (p<0.001). Almost all (94.7%; 18/19) CSP lesions were undifferentiated, and organoid differentiation was observed in 72.2% (13/18). There was a significant difference from the unclassified pattern with organoid differentiation (p<0.05).

CONCLUSIONS

Cellular differentiation and distribution are associated with microvascular architecture observed by M-NBI.

Diagnosis of Early Gastric Cancer by Magnifying Endoscopy with NBI from Viewpoint of Histological Imaging: Mucosal Patterning in terms of White Zone Visibility and Its Relationship to Histology

The diagnosis of early gastric cancer by magnifying endoscopy with NBI is based on two components: microvascular pattern and mucosal pattern. Mucosal patterns are characterized by a whitish edge, which has been named the white zone. Some cancerous areas showing a distinct white zone form clear mucosal patterns, whereas others showing a nondistinct white zone do not form mucosal patterns. The aim of the present study was to clarify the histological differences between these two types of area. In transverse sections of gastric epithelium, the lengths of intervening parts in areas showing a distinct white zone, a nondistinct white zone, and an invisible white zone were measured, and the depths of the crypts in these three types of area were also measured. The intervening parts in areas with a nondistinct or invisible white zone were shorter than those in areas with a distinct white zone (P < 0.05), and the crypts in the former areas were shallower than those in the latter (P < 0.01). Areas in which the intervening part were long and the crypts deep tended to show a distinct white zone, whereas areas with short intervening parts or shallow crypts tended to show a nondistinct or non-visible white zone.

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.

Comprehensive investigation of areae gastricae pattern in gastric corpus using magnifying narrow band imaging endoscopy in patients with chronic atrophic fundic gastritis

BACKGROUND

Barium radiographic studies have suggested the importance of evaluating areae gastricae pattern for the diagnosis of gastritis. Significance of endoscopic appearance of areae gastricae in the diagnosis of chronic atrophic fundic gastritis (CAFG) was investigated by image-enhanced endoscopy.

MATERIALS AND METHODS

 Endoscopic images of the corpus lesser curvature were studied in 50 patients with CAFG. Extent of CAFG was evaluated with autofluorescence imaging endoscopy. The areae gastricae pattern was evaluated with 0.2% indigo carmine chromoendoscopy. Micro-mucosal structure was examined with magnifying chromoendoscopy and narrow band imaging.

RESULTS

 In patients with small extent of CAFG, polygonal areae gastricae separated by a narrow intervening part of areae gastricae was observed, whereas in patients with wide extent of CAFG, the size of the areae gastricae decreased and the width of the intervening part of areae gastricae increased (p < 0.001). Most areae gastricae showed a foveola-type micro-mucosal structure (82.7%), while intervening part of areae gastricae had a groove-type structure (98.0%, p < 0.001). Groove-type mucosa had a higher grade of atrophy (p < 0.001) and intestinal metaplasia (p < 0.001) compared with foveola type.

CONCLUSIONS

 As extent of CAFG widened, multifocal groove-type mucosa that had high-grade atrophy and intestinal metaplasia developed among areae gastricae and increased along the intervening part of areae gastricae. Our observations facilitate our understanding of the development and progression of CAFG.