A case of a stuck mesh in the rectum after pelvic surgery

A 67-year-old woman was referred to our hospital for further evaluation of a positive fecal occult blood test. Colonoscopy revealed an elevated rectal lesion (10 mm in size) with a central depression. A rod-like object was noted in the center of the lesion. Magnifying endoscopy with narrow-band imaging showed obscure surface structures and dilated vessels. Magnifying endoscopy with crystal violet staining showed that the pit pattern had disappeared. These endoscopic findings suggested that the lesion was comprised of granulation tissue. A detailed medical history revealed that she had undergone a total hysterectomy with mesh placement for bladder prolapse. We reasoned that the mesh used during pelvic surgery might have penetrated the rectum. She underwent subsequent surgery to remove the mesh. Although most foreign bodies in the rectum are swallowed or self-inserted, pelvic surgery is another source of foreign bodies in the rectum.

Diagnostic Performance of a Novel Ultra-Thin Endoscopy under Narrow-Band Imaging for Superficial Squamous Cell Carcinoma of the Pharynx and Esophagus

This study aimed to evaluate the diagnostic utility of the ultra-thin endoscope (UTE) for superficial squamous cell carcinoma (SSCC) compared to magnifying endoscopy (ME) under narrow-band imaging. Participants underwent endoscopic examination, and images of pharyngeal and esophageal SCCs, as along with suspicious SSCC lesions, were collected using UTE and ME on the same day. Three image catalogs (UTE, ME-1, and ME-2) were created and reviewed by three expert endoscopists. ME-1 and ME-2 contained the same endoscopic images. The primary endpoint was the intra-observer agreement for diagnosing SCC. Eighty-six lesions (SCC = thirty-nine, non-SCC = forty-seven) in 43 participants were identified. The kappa values for the intra-observer agreement between UTE and ME-1 vs. the control (ME-1 vs. ME-2) were 0.74 vs. 0.84, 0.63 vs. 0.76, and 0.79 vs. 0.88, respectively. The accuracies for diagnosing SCC by UTE and ME-1 were 87.2% vs. 86.0%, 78.0% vs. 73,2%, and 75.6 vs. 82.6%, respectively, with no significant differences (p > 0.05). The rates of lesions that were diagnosed with confidence by UTE and ME-1 were 30.2% vs. 27.9%, 55.8% vs. 62.8%, and 58.1% vs. 55.8%, respectively. UTE demonstrates substantial diagnostic performance for SSCC in the pharynx and esophagus.

Gastric Juvenile Polyposis with Intramucosal Cancer Diagnosed by Magnifying Endoscopy with Narrow-band Imaging

Although gastric juvenile polyposis (GJP) often coexists with gastric cancer, a preoperative accurate diagnosis is still difficult to obtain. A 70-year-old woman was referred for epigastralgia and anemia. Esophagogastroduodenoscopy with a conventional endoscope showed numerous gastric polyps with no cancerous findings. Magnifying endoscopy with narrow-band imaging (M-NBI) showed cancerous findings, and a target biopsy revealed adenocarcinoma. Histopathological findings after endoscopic resection confirmed a diagnosis of juvenile polyposis with intramucosal adenocarcinoma. Genetic analyses revealed a germline pathogenic variant of SMAD4. A target biopsy using M-NBI and endoscopic resection proved useful for confirming the preoperative diagnosis of coexisting cancerous lesions in GJP.

Case report: Streptomycin combined with dacronin in painless magnifying endoscopy

RATIONALE

To analyze the effect of streptomyces protease combined with dyclonine in painless magnifying endoscopy.

PATIENT CONCERNS

A total of 100 patients who underwent magnification endoscopy in our hospital from January 2021 to June 2022 were retrospectively analyzed.

DIAGNOSES

The diagnoses were made by painless magnifying endoscopy and narrow-band imaging combined with pathological findings.

INTERVENTIONS

The patients were divided into the observation group and control group, the observation group was streptomyces protease combined with dyclonine group, and the control group was dyclonine group, 50 cases in each group. The visibility score under gastroscopy was compared between the 2 groups, and the morphological classification of gastric pit and collecting veins was observed. The detection rates of small lesions and early cancer were compared between the 2 groups. The examination time and adverse reactions were compared between the 2 groups.

OUTCOMES

Compared with the control group, the streptomyces protease combined with dyclonine group had better clear visibility and a higher detection rate of small lesions, but there was no significant difference in early cancer detection rate between the 2 groups. The examination time of streptomyces protease combined with dyclonine group was relatively prolonged, but there was no significant difference in the incidence of adverse reactions between the 2 groups.

LESSONS

Streptomyces protease combined with dyclonine plays a certain role in painless magnifying gastroscopy, which can improve the visibility of gastroscopy, improve the detection rate of small lesions, help to find gastric dysplasia and early gastric cancer diagnosis, and does not increase the incidence of adverse reactions.

The features of gastric epithelial reactive hyperplastic lesions under magnifying endoscopy combined with narrow-band imaging

BACKGROUND AND PURPOSE

Gastric reactive hyperplasia (RH) is a common benign lesion of the gastric mucosa that can be resolved by conservative treatment without endoscopic intervention. Some RH lesions are indistinguishable from low-grade intraepithelial neoplasia (LGIN) lesions of gastric mucosa under endoscopy. The aim of this study was to investigate the morphological features of RH lesions under magnifying endoscopy combined with narrow-band imaging (ME-NBI).

METHODS

A retrospective study of 653 patients with superficial suspicious lesions of gastric mucosa was performed. According to the pathological results of biopsies, the final included lesions were divided into the RH group (n = 88) and LGIN group (n = 138). We analysed the microvascular and microsurface patterns of these lesions under ME-NBI, extracted the most significant combination of endoscopic features of RH lesions, and evaluated their diagnostic performance.

RESULTS

ME-NBI characteristics that could distinguish RH lesions from LGIN lesions after univariate analysis were included in multivariate logistic regression. The results showed that ten characteristics, including intervening part (IP) length homogeneity, type III gastric pit pattern and homogeneity of marginal crypt epithelium (MCE), were statistically significant. Receiver operating characteristic (ROC) analysis showed that the triad of these features was the best combination for diagnosing RH lesions with an AUC of 0.886 (95% confidence interval; 0.842-0.929), the sensitivity of 85.5% and specificity of 79.5%.

CONCLUSIONS

The triad of IP length homogeneity, type III pit pattern and MCE homogeneity under ME-NBI helps endoscopists to identify gastric RH lesions, thereby avoiding unnecessary biopsy and repeat endoscopy due to misjudgment of neoplastic lesions.

Endoscopic manifestations and treatment outcomes of asymptomatic gastric metastases from primary lung adenocarcinoma: Report of two cases

Metastatic spread of lung adenocarcinoma to the stomach is rare and most gastric metastases are discovered at the advanced stage due to certain symptoms. The present study reported two cases of asymptomatic gastric metastases from lung adenocarcinoma presenting as diminutive nodules or erosion endoscopically. The manifestations were also visualized under magnifying endoscopy with blue laser imaging (BLI-ME), the two cases share certain common characteristics under BLI-ME, such as an obviously widened intervening part and extended subepithelial capillary network, which indicated that lesions developed beneath the superficial epithelium. Target biopsy and further immunohistochemical staining confirmed that the gastric lesions were metastatic from primary lung cancer. None of the two patients were candidates for surgery due to multiple distant metastases, but the gastric metastases regressed to scars after systemic anticancer therapy. These two cases were presented in order to improve the current understanding of the endoscopic manifestations of early gastric metastases from lung cancer, and the outcomes may demonstrate that systemic treatment is effective for eliminating early gastric metastatic lesions.

Colonic mucosa-associated lymphoid tissue lymphoma: A case report

Background

Mucosa-associated lymphoid tissue (MALT) lymphoma is a group of extranodal lymphomas that originate from B cells. Primary colonic MALT lymphoma is a rare disease, and there is no consensus on its endoscopic features and standard therapies. It is essential to raise awareness of colonic MALT lymphoma and choose the appropriate treatment.

Case presentation

In this case report, we describe a 0-IIb-type lesion that was found by electronic staining endoscopy and magnifying endoscopy. The patient underwent a definitive diagnostic ESD for diagnosis. The patient was evaluated for lymphoma after diagnostic ESD according to the Lugano 2014 evaluation criteria, which are divided into imaging remission on the basis of CT and/or magnetic resonance imaging (MRI) evaluation and metabolic remission on the basis of PET-CT evaluation. Based on the PET-CT results suggesting increased glucose metabolism in the sigmoid colon, the patient underwent additional surgical treatment. According to the pathological results of the surgery, we found that ESD could treat such lesions, which may provide a new option for colorectal MALT lymphoma.

Conclusion

The low incidence of colorectal MALT lymphoma, especially for 0-IIb lesions, which are difficult to detect, requires the use of electronic staining endoscopy to improve the detection rate. The combination with magnification endoscopy can improve the understanding of colorectal MALT lymphoma, which ultimately requires pathological support for diagnosis. According to our experience with the present patient case, ESD seems to be a feasible and economical choice for the treatment of massive colorectal MALT lymphoma. However, the combined application of ESD and another therapy scheme needs further clinical investigation.

Magnifying Endoscopy with Narrow-Band Imaging for Duodenal Neuroendocrine Tumors

Duodenal neuroendocrine tumors (NETs) are rare subepithelial tumors that arise from the neuroendocrine cells beneath the epithelial layer. However, an accurate histopathological diagnosis is difficult when tissue samples are obtained using conventional endoscopic forceps biopsy alone. This study aimed to evaluate the magnifying endoscopy with narrow-band imaging (ME-NBI) findings of duodenal NETs. We retrospectively analyzed a database of 22 duodenal NETs from 21 patients who underwent ME-NBI between January 2011 and June 2022. The ME-NBI, endosonographic, and histopathologic findings of duodenal NETs were analyzed. Nineteen lesions were located in the bulb, two were located in the superior duodenal angle, and one was located in the second portion of the duodenum. Eighteen lesions (82%) had IIa morphology, and nine (41%) had central depression on the surface. On endoscopic ultrasonography, almost all lesions (20/22, 91%) were located in the second and/or third layers, and the median tumor size was 6 mm. During ME-NBI, the microsurface pattern was regular in 18 lesions (82%) and absent in 4 (18%). The microvascular pattern was regular in 17 lesions (77%), irregular in 4 (18%), and absent in 1 (5%). Thickened subepithelial vessels were observed in 15 (68%) lesions. There was no difference in tumor size according to the presence or absence of thickened subepithelial vessels (6.1 ± 1.8 mm vs. 5.9 ± 3.8 mm, p = 0.860). In conclusion, the characteristic ME-NBI findings of duodenal NETs were regular microsurface and microvascular patterns and the presence of thickened subepithelial vessels. These ME-NBI features may be useful for differentiating duodenal NETs from other duodenal subepithelial lesions.

Current status and perspectives for endoscopic diagnosis of superficial nonampullary duodenal epithelial tumors

In recent years, there have been significant advances in the endoscopic resection (ER) procedures of superficial nonampullary duodenal epithelial tumors (SNADETs). A preoperative endoscopic diagnosis is thus deemed necessary in determining the indication for subsequent ER. For the histologic and endoscopic diagnosis of SNADETs, understanding the mucin phenotype is inevitable. Recently, two diagnostic algorithms for the differential diagnosis of SNADETs from nonneoplastic lesions under magnifying endoscopy with narrow-band imaging have been proposed. In addition, various endoscopic approaches have been proposed to differentiate low- and high-grade adenomas/carcinomas, including white light endoscopy, magnifying image-enhanced endoscopy, and endocytoscopy. These methods, however, have not been standardized with respect to the classification of their findings and the validation of their diagnostic accuracy. Moreover, there are still concerns with respect to the histologic criteria required to establish a SNADETs diagnosis. Standardization in the histologic and endoscopic diagnosis of SNADETs is needed.

Endoscopic Grading of Gastric Intestinal Metaplasia Using Magnifying and Nonmagnifying Narrow-Band Imaging Endoscopy

Several endoscopic findings obtained by magnifying image-enhanced endoscopy (IEE) are reportedly correlated with gastric intestinal metaplasia (IM); however, the differences between magnifying and nonmagnifying IEE for the diagnosis of gastric IM remain unknown. This study included 100 consecutive patients who underwent narrow-band imaging endoscopy. Four areas of the stomach were evaluated using nonmagnifying and magnifying IEE. Light-blue crest (LBC), white opaque substance (WOS), and endoscopic grading of the gastric IM (EGGIM) were assessed. The concordance rates between nonmagnifying and magnifying IEE were 80.5% for LBC and 93.3% for WOS. The strength of agreement between each observation technique showed good reproducibility, with a kappa value of 0.69 and 0.83 for LBC and WOS, respectively. The individual EGGIM score indicated a good correlation between nonmagnifying and magnifying IEE (concordance rate, 75%; kappa value, 0.67). The prevalence of a high EGGIM score in patients with and without gastric cancer (GC) showed a significant difference both with nonmagnifying IEE (odds ratio (OR), 3.3; 95% confidence interval (CI), 1.2-9.0), and magnifying IEE (OR, 3.1; 95% CI, 1.1-8.9). Nonmagnifying IEE has the potential to stratify the individual risk of GC, similar to magnifying IEE, warranting further investigation with histological assessment.

Current status of endoscopic detection, characterization and staging of superficial esophageal squamous cell carcinoma

BACKGROUND

This review focuses on the current status of endoscopic detection, characterization and tumour category staging of oesophagealsquamous cell carcinoma.

DETECTION

The diagnostic yield of white-light imaging is limited and narrow-band imaging has demonstrated a better performance for detecting oesophageal cancer. Narrow-band imaging has also shown similar sensitivity and superior specificity to iodine staining.

CHARACTERIZATION

Accurate differentiation between cancerous and non-cancerous lesions can be achieved by magnifying narrow-band imaging or iodine staining with confirmation of a pink-colour sign. A per-patient analysis of a randomized study showed similar sensitivities, specificities and overall accuracies of magnifying narrow-band imaging and iodine staining of 82.2%, 95.1% and 91.2%, and 80.5%, 94.3% and 90.5%, respectively.

TUMOUR-STAGING

The diagnostic capability of endoscopic ultrasonography after conventional and narrow-band imaging in terms of tumour depth was evaluated in a multicentre prospective study. Endoscopic ultrasonography did not significantly improve the accuracy for distinguishing between mucosal or submucosal microinvasive cancer and deeper cancers from 72.9 to 74.0%, suggesting that additional endoscopic ultrasonography did not improve the diagnostic accuracy. In addition, endoscopic ultrasonography increased the incidence of overdiagnosis, defined as a diagnosis of cancer depth greater than the actual depth, by 6.6%. The risk of overdiagnosis by endoscopic ultrasonography was reconfirmed in two systematic reviews.

CONCLUSIONS

Narrow-band imaging is currently considered as the standard modality for the detection and characterization of oesophageal cancer. The risk of overdiagnosis should be considered when applying endoscopic ultrasonography for the evaluation of tumour invasion depth of superficial oesophageal squamous cell carcinoma.

Current status of diagnostic and therapeutic colonoscopy in Japan: The Japan Endoscopic Database Project

OBJECTIVES

The Japan Endoscopy Database Project was initiated to develop the world's largest endoscopy data repository. This study describes the first phase of the colonoscopy project in Japan.

METHODS

Data were aggregated offline by integrating information from the endoscopy database software from January 2015 through March 2017. The study population included all patients who underwent colonoscopy at eight centers.

RESULTS

A total of 31,395 patients who underwent 38,497 colonoscopy procedures were registered. The majority of procedures were performed for screening (n = 14,156), followed by fecal immunochemical test positivity (n = 3960), abdominal symptoms (n = 3864), post-colorectal surgery surveillance (n = 3431), post-endoscopic treatment surveillance (n = 3757), thorough pre-treatment examination (n = 2822), and therapeutic purposes (n = 6507). In the screening group, advanced cancers, early cancers, and adenomas were diagnosed endoscopically in 2.1%, 1.3%, and 28.7% of cases, respectively, while in the fecal immunochemical test-positive group, they were diagnosed in 2.5%, 1.9%, and 41.6% of cases, respectively. The incidence of complications was 0.177% and 0.152% in the screening and fecal immunochemical test-positive groups, respectively. The therapeutic procedures included 1446 cold forceps polypectomy procedures, 4770 cold snare polypectomy procedures, 368 hot biopsies, 2998 hot snare polypectomy procedures, 9775 endoscopic or piecemeal endoscopic mucosal resections, and 1660 endoscopic submucosal dissections. A total of 173 procedure-related complications (0.82%) occurred in 21,017 therapeutic procedures performed in 15,744 patients.

CONCLUSIONS

The first phase of the Japan Endoscopy Database Project established the proportions of the diagnostic and therapeutic colonoscopy procedures, and complication rates in real-world settings.

Endoscopic Classifications of Early Gastric Cancer: A Literature Review

Simple Summary

Throughout the years, endoscopic technologies have advanced to facilitate better assessment of gastric lesions and early detection of gastric cancer. With improvements in conventional white light endoscopy, we have also witnessed the development of newer endoscopic diagnostic modalities, giving rise to several classifications for early gastric cancer. Different endoscopic classifications of early gastric based on several endoscopic diagnostic modalities were included in this review. In addition to this, newer and novel endoscopic classifications that were specifically developed for the stomach for assessing and diagnosing gastric lesions have also been included. Illustrative representations of each classification have also been provided to aid readers in better understanding of these endoscopic classifications of early gastric cancer.

Abstract

Endoscopic technologies have been continuously advancing throughout the years to facilitate improvement in the detection and diagnosis of gastric lesions. With the development of different endoscopic diagnostic modalities for EGC, several classifications have been advocated for the evaluation of gastric lesions, aiming for an early detection and diagnosis. Sufficient knowledge on the appearance of EGC on white light endoscopy is fundamental for early detection and management. On the other hand, those superficial EGC with subtle morphological changes that are challenging to be detected with white light endoscopy may now be clearly defined by means of image-enhanced endoscopy (IEE). By combining magnifying endoscopy and IEE, irregularities in the surface structures can be evaluated and highlighted, leading to improvements in EGC diagnostic accuracy. The main scope of this review article is to offer a closer look at the different classifications of EGC based on several endoscopic diagnostic modalities, as well as to introduce readers to newer and novel classifications, specifically developed for the stomach, for the assessment and diagnosis of gastric lesions.

"Pink Pattern" Visualized in Magnifying Endoscopy With Narrow-Band Imaging Is a Novel Feature of Early Differentiated Gastric Cancer: A Bridge Between Endoscopic Images and Histopathological Changes

Background: A pink color change occasionally found by us under magnifying endoscopy with narrow-band imaging (ME-NBI) may be a special feature of early gastric cancer (EGC), and was designated the “pink pattern”. The purposes of this study were to determine the relationship between the pink pattern and the cytopathological changes in gastric cancer cells and whether the pink pattern is useful for the diagnosis of EGC.

Methods: The color features of ME-NBI images and pathological images of cancerous gastric mucosal surfaces were extracted and quantified. The cosine similarity was calculated to evaluate the correlation between the pink pattern and the nucleus-to-cytoplasm ratio of cancerous epithelial cells. Two diagnostic tests were performed by 12 endoscopists using stored ME-NBI images of 185 gastric lesions to investigate the diagnostic efficacy of the pink pattern for EGC. The diagnostic values, such as the area under the curve (AUC), the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), of test 1 and test 2 were compared.

Results: The cosine similarity between the color values of ME-NBI images and pathological images of 20 lesions was at least 0.744. The median AUC, accuracy, sensitivity, specificity, PPV, and NPV of test 2 were significantly better than those of test 1 for all endoscopists and for the junior and experienced groups.

Conclusions: The pink pattern observed in ME-NBI images correlated strongly with the change in the nucleus-to-cytoplasm ratio of gastric epithelial cells, and could be considered a useful marker for the diagnosis of differentiated EGC.

Real-time artificial intelligence for endoscopic diagnosis of early esophageal squamous cell cancer (with video)

BACKGROUND AND AIMS

Endoscopic diagnosis of early esophageal squamous cell cancer (ESCC) is complicated and dependent on operators' experience. This study aimed to develop an artificial intelligence (AI) model for automatic diagnosis of early ESCC.

METHODS

Non-magnifying and magnifying endoscopic images of normal/noncancerous lesions, early ESCC, and advanced esophageal cancer (AEC) were retrospectively obtained from Qilu Hospital of Shandong University. A total of 10,988 images from 5075 cases were chosen for training and validation. Another 2309 images from 1055 cases were collected for testing. One hundred and four real-time videos were also collected to evaluate the diagnostic performance of the AI model. The diagnostic performance of the AI model was compared with endoscopists by magnifying images and the assistant efficiency of the AI model for novices was evaluated.

RESULTS

The AI diagnosis for non-magnifying images showed a per-patient accuracy, sensitivity, and specificity of 99.5%, 100%, 99.5% for white light imaging, and 97.0%, 97.2%, 96.4% for optical enhancement/iodine straining images. Regarding diagnosis for magnifying images, the per-patient accuracy, sensitivity, and specificity were 88.1%, 90.9%, and 85.0%. The diagnostic accuracy of the AI model was similar to experts (84.5%, P = 0.205) and superior to novices (68.5%, P = 0.005). The diagnostic performance of novices was significantly improved by AI assistance. When it comes to the diagnosis for real-time videos, the AI model showed acceptable performance as well.

CONCLUSIONS

The AI model could accurately recognize early ESCC among noncancerous mucosa and AEC. It could be a potential assistant for endoscopists, especially for novices.

Pyogenic Granuloma Mimicking T1 Colorectal Carcinoma

Pyogenic granuloma (PG), a benign capillary hemangioma, is extremely rare in the colon. Here, we present a case of PG that was difficult to distinguish from T1 (deep submucosal invasive) colorectal carcinoma. A 57-year-old woman with no remarkable history was referred to us for a detailed investigation of a positive fecal occult blood test. Colonoscopy revealed a reddish, irregular-shaped, protruding lesion (5 mm) in the rectum. We performed endoscopic mucosal resection of the lesion as total excisional biopsy because T1 colorectal carcinoma was suspected, despite the lesion’s small size after observation by magnifying endoscopy. Histologically, the protruding lesion mainly consisted of numerous capillaries lined with plump and flat endothelial cells without signs of malignancy. Colorectal carcinoma, on the other hand, is composed of tall columnar atypical epithelial cells showing neoplastic proliferation. Thus, cell morphology is completely different between PG and colorectal carcinoma. The final diagnosis was colonic PG with a negative vertical margin. In conclusion, physicians should be aware of a colorectal protruding lesion devoid of malignant potential, as in this case, where the lesion was difficult to diagnose accurately and to distinguish from T1 colorectal carcinoma on magnifying endoscopy. Physicians should consider PG as a differential diagnosis in similar cases.

Establishing an endoscopic diagnostic process system (M-system) for gastric MALT lymphoma of superficial-spreading type

OBJECTIVE

Gastric mucosa-associated lymphoid tissue lymphoma is a rare disease, which is associated with a low endoscopic diagnostic accuracy even on tissue biopsy. We aimed to establish a diagnostic process system (M-system) using detailed magnifying endoscopy images to improve the diagnostic efficiency of this disease.

METHODS

First, 34 cases from 16 patients with the diagnosis of mucosa-associated lymphoid tissue lymphoma were collected as the study group. The control group included randomly selected patients who were diagnosed with early differentiated carcinoma, undifferentiated carcinoma or inflammation. Then, the endoscopic images of these patients were analyzed by senior physicians. Finally, the M-system was established based on the data extracted from the images reviewed, and its diagnostic efficiency for mucosa-associated lymphoid tissue lymphoma was validated by the junior physicians.

RESULTS

A series of elements with high sensitivity and specificity for the diagnosis of mucosa-associated lymphoid tissue lymphoma on endoscopic images were extracted for the establishment of the M-system. Using the M-system, the diagnostic accuracy, sensitivity, specificity and correct indices of mucosa-associated lymphoid tissue lymphoma rose from 65.4 to 79.4%, 41.2 to 76.5%, 73.5 to 80.4% and 0.147 to 0.569%, respectively, all of which were statistically significant.

CONCLUSIONS

The M-system can improve the diagnostic accuracy of mucosa-associated lymphoid tissue lymphoma of the superficial-spreading type on detailed magnifying endoscopy. This would help in the early diagnosis of the disease and treatment, which would translate into improved clinical outcomes.

Diagnostic performance of magnifying blue laser imaging versus magnifying narrow-band imaging for identifying the depth of invasion of superficial esophageal squamous cell carcinoma

Identifying the depth of invasion (DOI) of superficial esophageal squamous cell carcinoma (SESCC) is crucial to determine the indication for endoscopic resection. This retrospective, single-center study aimed to evaluate the diagnostic efficacy of magnifying blue laser imaging (M-BLI) compared with white-light imaging (WLI) or magnifying narrow-band imaging (M-NBI) for identifying the DOI of SESCC. A total of 160 consecutive patients with SESCCs who underwent endoscopic submucosal dissection were enrolled in this study. Still images of the lesion were obtained using WLI, M-BLI and M-NBI prior to endoscopic submucosal dissection. Three endoscopists retrospectively evaluated the DOI using WLI according to non-magnifying findings and using M-BLI and M-NBI images according to the magnifying endoscopic classification of the Japan Esophageal Society. The diagnostic accuracy of each modality was compared using the chi-square test. The DOIs in 160 SESCCs evaluated pathologically were as follows: invasion to the epithelium or lamina propria mucosa in 130, invasion to the lamina muscularis mucosa or submucosa to a depth ≤ 200 μm in 18, and invasion to the submucosa to a depth > 200 μm in 12. The overall diagnostic accuracy rates of WLI, M-BLI, M-NBI, WLI with M-BLI (WLI + M-BLI), and WLI with M-NBI (WLI + M-NBI) were 86.9, 91.2, 90.6, 95.6 and 94.4%, respectively. Significant differences were found between WLI and WLI + M-BLI or WLI + M-NBI (P = 0.006 and P = 0.021, respectively). The concordance of intrapapillary capillary loops between M-BLI and M-NBI was 91.2%. The kappa coefficients for interobserver variability of the three endoscopists for M-BLI and M-NBI were 0.728/0.649/0.792 and 0.729/0.666/0.791, respectively, while those for intraobserver variability were 0.919/0.746/0.778 and 0.736/0.720/0.745, respectively. Similar to M-NBI, M-BLI was useful in predicting the DOI of SESCCs.

Usefulness of vessel plus surface classification system for the diagnosis of early gastric cancer after Helicobacter pylori eradication

Background

It has been reported that it is sometimes difficult to make a diagnosis of gastric cancer detected after Helicobacter pylori (H. pylori) eradication. Therefore, we conducted a study to determine the usefulness of magnifying endoscopy using vessel plus surface classification system for making a diagnosis of early gastric cancer after H. pylori eradication.

Method

Usefulness of the markers of the vessel plus surface classification system for diagnosing gastric cancer using magnifying endoscopy with narrow-band imaging was investigated for gastric cancer detected after H. pylori eradication (H. pylori-eradicated group) vs. H. pylori-positive gastric cancer (H. pylori-positive group).

Results

85 lesions were included in this study. The H. pylori-eradicated group comprised 27 lesions, whereas the H. pylori-positive group comprised 58 lesions. As for magnified endoscopic findings based on the vessel plus surface classification system, the respective positivity rates in the H. pylori-eradicated group vs. those in the H. pylori-positive group were as follows: demarcation line, 100% (27/27) vs. 100% (58/58); irregular microvascular pattern, 100% (27/27) vs. 100% (58/58); and irregular microsurface pattern, 78% (21/27) vs. 95% (55/58). There was no significant difference in the positivity rates of the demarcation line and irregular microvascular pattern between the groups. The positivity rate of the irregular microsurface pattern was significantly lower in the H. pylori-eradicated group than in the H. pylori-positive group (P=0.03).

Conclusion

We presume that the microvascular pattern is more useful than the microsurface pattern as a diagnostic marker in cases of gastric cancer detected after H. pylori eradication.

Application of artificial intelligence using a convolutional neural network for diagnosis of early gastric cancer based on magnifying endoscopy with narrow-band imaging

BACKGROUND AND AIM

Magnifying endoscopy with narrow-band imaging (ME-NBI) has made a huge contribution to clinical practice. However, acquiring skill at ME-NBI diagnosis of early gastric cancer (EGC) requires considerable expertise and experience. Recently, artificial intelligence (AI), using deep learning and a convolutional neural network (CNN), has made remarkable progress in various medical fields. Here, we constructed an AI-assisted CNN computer-aided diagnosis (CAD) system, based on ME-NBI images, to diagnose EGC and evaluated the diagnostic accuracy of the AI-assisted CNN-CAD system.

METHODS

The AI-assisted CNN-CAD system (ResNet50) was trained and validated on a dataset of 5574 ME-NBI images (3797 EGCs, 1777 non-cancerous mucosa and lesions). To evaluate the diagnostic accuracy, a separate test dataset of 2300 ME-NBI images (1430 EGCs, 870 non-cancerous mucosa and lesions) was assessed using the AI-assisted CNN-CAD system.

RESULTS

The AI-assisted CNN-CAD system required 60 s to analyze 2300 test images. The overall accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the CNN were 98.7%, 98%, 100%, 100%, and 96.8%, respectively. All misdiagnosed images of EGCs were of low-quality or of superficially depressed and intestinal-type intramucosal cancers that were difficult to distinguish from gastritis, even by experienced endoscopists.

CONCLUSIONS

The AI-assisted CNN-CAD system for ME-NBI diagnosis of EGC could process many stored ME-NBI images in a short period of time and had a high diagnostic ability. This system may have great potential for future application to real clinical settings, which could facilitate ME-NBI diagnosis of EGC in practice.

Magnifying endoscopy in detecting early gastric cancer: A network meta-analysis of prospective studies

BACKGROUND

Conventional white-light imaging endoscopy (C-WLI) had a significant number of misdiagnosis in early gastric cancer (EGC), and magnifying endoscopy (ME) combined with different optical imaging was more accurate in the diagnosis of EGC. This study aimed to evaluate the accuracy of ME and compare the accuracy of ME with different optical imaging in detecting EGC.

METHODS

A comprehensive literature search was conducted to identify all relevant studies. Pair-wise meta-analysis was conducted to evaluate the accuracy of ME, and Bayesian network meta-analysis was performed to combine direct and indirect evidence and estimate the relative effects.

RESULTS

Eight prospective studies were identified with a total of 5948 patients and 3 optical imaging in ME (ME with WLI (M-WLI), ME with narrow-band imaging (M-NBI), and ME with blue laser imaging (M-BLI)). Pair-wise meta-analysis showed a higher accuracy of ME than C-WLI (OR: 2.97, 95% CI: 1.68∼5.25). In network meta-analysis, both M-NBI and M-BLI were more accurate than M-WLI (OR: 2.56, 95% CI: 2.13∼3.13; OR: 3.13, 95% CI: 1.85∼5.71). There was no significant difference between M-NBI and M-BLI.

CONCLUSION

ME was effective in improving the detecting rate of EGC, especially with NBI or BLI.

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.

Diagnosis of early gastric cancer using image enhanced endoscopy: a systematic approach

This paper provides an overview of the principles of a vessel plus surface (VS) classification system to explain the diagnostic system of early gastric cancer using image-enhanced magnifying endoscopy. Furthermore, this paper introduces the magnifying endoscopy simple diagnostic algorithm for gastric cancer (MEADA-G) developed according to the VS classification system, with a description of the procedures performed for diagnosis. In addition to the diagnostic system, white opaque substance (WOS), light blue crest (LBC), white globe appearance (WGA), and vessels within epithelial circle (VEC) patterns, which are representative findings that can be observed in the gastric mucosa by image-enhanced magnifying endoscopy, are also described. Image-enhanced magnifying endoscopy is particularly useful in the diagnosis of differentiated-type early gastric cancer. It is important to use the appropriate clinical strategies based on a comprehensive understanding of the usefulness and limitations of the diagnostic system described in this paper.

Endoscopic findings of gastric mixed adenoneuroendocrine carcinoma: A case report

RATIONALE

Gastric mixed adenoneuroendocrine carcinoma (gMANEC) is a rare malignant tumor. Most gMANECs are diagnosed at an advanced stage and have a worse prognosis than gastric adenocarcinoma. In order to improve the prognosis, it is necessary to diagnose gMANEC at an early stage. However, the endoscopic features of early gMANECs are unclear. We, herein, report a case of early gMANEC that showed characteristic magnifying endoscopic findings.

PATIENT CONCERNS

A 78-year-old man was referred to our institution for endoscopic resection of a gastric lesion. He had a medical history of distal gastrectomy due to early gastric cancer with negative surgical margins 9 years previously.

DIAGNOSIS

Esophagogastroduodenoscopy showed a reddish depressed lesion on the suture line of the gastric remnant, which was classified as type 0-IIc according to the Paris classification. ME-NBI at the oral side of the lesion revealed the absence of the microsurface pattern (MSP) and scattered microvessels with dilation and caliber variation, while ME-NBI at the anal side showed an irregularly tubular MSP. An endoscopic forceps biopsy showed a well- to moderately differentiated adenocarcinoma.

INTERVENTIONS

We performed endoscopic submucosal dissection, and en bloc resection of the tumor was successfully achieved.

OUTCOMES

The histological findings showed two distinct components: neuroendocrine carcinoma (NEC) and well-differentiated adenocarcinoma, which comprised ∼60% and 40% of the tumor, respectively. The NEC component corresponded to the site with the absence of an MSP and scattered microvessels on ME-NBI, while the well-differentiated adenocarcinoma component corresponded to the site with an irregularly tubular MSP. The pathological diagnosis was mixed adenoneuroendocrine carcinoma, infiltrating into the deep submucosal layer.

LESSONS

We propose that the absence of an MSP plus an irregular MSP is characteristics of gMANEC, which was useful for the diagnosis of gMANEC before treatment.

Sessile serrated adenoma/polyp showed rapid malignant transformation in the final 13 months

Based on the concept of the adenoma-carcinoma sequence, most colorectal cancers are considered to arise from conventional adenomas. However, recent studies suggested that a subset of colorectal cancers develop through the serrated neoplastic pathway. It has also been documented that serrated polyps can rapidly transform into invasive cancers even when they are small in size. We now describe a case of a sessile serrated adenoma/polyp which had been followed up for 4 years but eventually showed rapid transformation into an advanced cancer accompanied by a remarkable morphological change within only 13 months. Retrospective genetic and epigenetic analyses showed microsatellite instability, CpG island methylator phenotype-positive, and BRAF mutation in the lesion, suggesting the tumor had developed through the serrated neoplastic pathway. This case may provide valuable information about the natural history of sessile serrated adenoma/polyps which eventually progress to advanced cancers.

Endoscopic prediction of advanced histology in colorectal lesions sized <10 mm using the Japan Narrow-band imaging Expert Team classification

BACKGROUND AND AIM

Endoscopic diagnosis of advanced histology in colorectal lesions sized <10 mm is essential for appropriate selection of resection methods. The Japan Narrow-band imaging Expert Team (JNET) classification has been recently validated for the evaluation of colorectal lesions. Our objective was to investigate the diagnostic value of the JNET classification for advanced histology in colorectal lesions sized <10 mm.

METHODS

We enrolled 680 patients with 1472 colorectal lesions sized <10 mm diagnosed according to the JNET classification and who subsequently underwent endoscopic or surgical resection between January and December 2017. We retrospectively examined the relationship between the JNET findings and pathological histology. Multivariate analysis was carried out to assess the predictive power of the JNET findings and clinical characteristics of lesions.

RESULTS

Advanced histology was present in 29 (2.0%) lesions. Advanced histology was absent in 68 lesions diagnosed as JNET type 1, whereas 1389 lesions diagnosed as JNET type 2A included 19 lesions of advanced histology (1.4%) with high-grade dysplasia alone. Eleven lesions diagnosed as JNET type 2B comprised eight lesions of advanced histology (72.7%) with four high-grade dysplasia and four submucosal invasive cancer, and two lesions diagnosed as JNET type 3 were submucosal invasive cancer. Multivariate analysis showed that JNET type 2B + 3 was a stronger predictive factor for advanced histology than other clinical risk factors.

CONCLUSION

Narrow-band imaging with magnification according to the JNET classification may be a useful modality for identification of advanced histology in colorectal lesions sized <10 mm.

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.

Generation of magnifying endoscopic images of gastric neoplasms based on an all-in-focus algorithm

BACKGROUND AND AIM

Magnifying endoscopy is useful for diagnosis of early gastrointestinal neoplasms by visualizing microvascular (MV) and microsurface (MS) structures of the mucosa when combined with image-enhanced endoscopy. However, precise control of the endoscope is needed because the depth of focus is narrow and the target may move. These problems may be overcome by the all-in-focus (AIF) technique, which was developed in the engineering field. The aim of the study was to evaluate magnifying endoscopic image with AIF algorithm.

METHODS

Twenty gastric neoplasms were examined. Images were acquired at 80× magnification and converted to endoscopic images with an AIF algorithm (EI-AIF). The focus area and MV and MS patterns in the original image and the EI-AIF were compared on a 5-point Likert scale, where 5 indicates that the EI-AIF was superior. Intraclass correlation coefficients (ICCs) were used to assess the inter-evaluator reliability. An image quality measurement value was calculated for each image as an indicator of the degree of focus.

RESULTS

The scores for focus area, MV, and MS were 4.78 ± 0.45 (ICC = 0.63), 4.12 ± 0.76 (ICC = 0.70), and 4.72 ± 0.52 (ICC = 0.45), respectively, with the EI-AIF significantly superior for all three items (P < 0.05 by Student's t-test). ICCs for the focus area and MV were > 0.60, indicating strong inter-evaluator reliability. Image quality measurement was higher for the EI-AIF compared with the original image in every case.

CONCLUSIONS

Endoscopic observation with AIF algorithm gives a better image quality that allows easier evaluation of MV and MS patterns. This technique may resolve the difficulties with magnifying endoscopic observation.

Genetic alterations related to endoscopic treatment of colorectal tumors

Background and Aim

Genetic indicators of endoscopic resection for colorectal carcinoma remain inconclusive. This study analyzed genetic changes in early colorectal tumors that could inform decisions for endoscopic procedures.

Methods

A total of 83 colorectal tumors from 81 patients, including adenoma (n = 7), Tis–T1a (n = 22), T1b (n = 14), and advanced carcinoma (n = 40), were analyzed. Tis tumors (n = 16) and some T1 carcinomas (n = 11) were analyzed as mixed adenomas and carcinomas. Lesions were laser‐capture microdissected for DNA extraction, and targeted sequencing of 50 cancer‐related genes was performed. Genetic data were then correlated with clinical records, including magnifying endoscopic findings.

Results

Numbers of gene alteration rates in TP53 and SMAD4 increased with tumor progression from adenoma to carcinoma. Frequencies of mutant variants in TP53 (P = 0.004) and rates of copy number loss in SMAD4 (P = 0.006) increased in carcinoma components of mixed tumors compared to adenoma components. Moreover, adenoma components of T1b carcinomas had higher TP53 mutation rates than Tis or T1a carcinomas (P = 0.011) and pure adenomas (P = 0.026). Gene alterations in TP53 (P = 0.0055) and SMAD4 (P = 0.0055) increased in cases with irregular surface patterns of magnifying endoscopic findings.

Conclusions

Numbers of copy number variations and TP53 and SMAD4 alterations were related to colorectal tumor progression. TP53 alteration rates in adenoma components were high in T1b carcinomas, warranting complete treatment with en bloc resection. Magnifying endoscopic findings might reflect the genetic status of colorectal tumors.

Risk factors associated with histological upgrade of gastric low-grade dysplasia on pretreatment biopsy

OBJECTIVES

Histological discrepancies between biopsy and resection specimens are common. In this study, we aimed to analyze the risk factors predicting histological upgrade or downgrade of biopsy-diagnosed gastric low-grade dysplasia (LGD).

METHODS

The medical records of patients with 104 biopsy-diagnosed gastric LGD from January 2011 to December 2017 were collected. The association of endoscopic characteristics with histological discrepancies between the biopsy and resection specimens was analyzed. The risk factors for histological upgrade were studied using the multivariate analysis.

RESULTS

Among the 104 lesions, 88 were removed by endoscopic resection and 16 were monitored. The upgrade and downgrade rates of the pathological diagnosis were 48.9% and 12.5%, respectively. Lesion size >20 mm, surface redness and positive results in magnifying endoscopy with narrow band imaging (ME-NBI) were risk factors for histological upgrade. Compared with the negative ME-NBI group, the positive ME-NBI group had a higher upgrade rate (56.8% vs 7.1%) but a lower downgrade rate (2.7% vs 64.3%). In addition, 11 of the 16 the gastric LGD with negative ME-NBI findings were monitored, and all 11 lesions regressed to gastritis during follow-up.

CONCLUSIONS

Endoscopic resection should be recommended in cases of LGD showing surface redness, with a lesion size of >20 mm or positive ME-NBI result, whereas regular follow-up may be an option for LGD with negative ME-NBI result.

Validation study for development of the Japan NBI Expert Team classification of colorectal lesions

BACKGROUND AND AIM

The Japan narrow-band imaging (NBI) Expert Team (JNET) was organized to unify four previous magnifying NBI classifications (the Sano, Hiroshima, Showa, and Jikei classifications). The JNET working group created criteria (referred to as the NBI scale) for evaluation of vessel pattern (VP) and surface pattern (SP). We conducted a multicenter validation study of the NBI scale to develop the JNET classification of colorectal lesions.

METHODS

Twenty-five expert JNET colonoscopists read 100 still NBI images with and without magnification on the web to evaluate the NBI findings and necessity of the each criterion for the final diagnosis.

RESULTS

Surface pattern in magnifying NBI images was necessary for diagnosis of polyps in more than 60% of cases, whereas VP was required in around 90%. Univariate/multivariate analysis of candidate findings in the NBI scale identified three for type 2B (variable caliber of vessels, irregular distribution of vessels, and irregular or obscure surface pattern), and three for type 3 (loose vessel area, interruption of thick vessel, and amorphous areas of surface pattern). Evaluation of the diagnostic performance for these three findings in combination showed that the sensitivity for types 2B and 3 was highest (44.9% and 54.7%, respectively), and that the specificity for type 3 was acceptable (97.4%) when any one of the three findings was evident. We found that the macroscopic type (polypoid or non-polypoid) had a minor influence on the key diagnostic performance for types 2B and 3.

CONCLUSION

Based on the present data, we reached a consensus for developing the JNET classification.

A training program of a new simplified classification of magnified narrow band imaging for superficial esophageal squamous cell carcinoma

BACKGROUND AND AIM

Optimal staging of the invasion depth of superficial esophageal squamous cell carcinoma is vital before endoscopic treatment. A new simplified magnified narrow-band imaging (M-NBI) classification system based on vascular architecture has recently been developed by the Japan Esophageal Society; however, its validity remains uncertain.

METHODS

A total of 11 experienced and 11 inexperienced endoscopists were invited to join an endoscopic training program, which was composed of pretest, educational section, and post-test. The pretest and post-test sections included a set of endoscopic photos from 40 subjects with superficial esophageal squamous cell carcinoma with various invasion depths. Each subject appeared twice in the test, one with white-light imaging (WLI) only and the other with both WLI and M-NBI. The educational section included lectures and video demonstrations.

RESULTS

The accuracy of WLI alone and combined with M-NBI at baseline were 0.53, 0.57 and 0.43, 0.41 for the experienced and inexperienced endoscopists, respectively, which then improved to 0.57, 0.63 and 0.49, 0.52 after training. Inter-observer agreement (k-value) of WLI alone and combined WLI and M-NBI for the experienced and inexperienced endoscopists also improved from 0.61, 0.61, and 0.61, 0.53 to 0.68, 0.71, and 0.71, 0.59, respectively. Multivariate analysis revealed that the educational course but not experience in endoscopy, NBI, or magnification significantly improved the diagnostic accuracy. M-NBI had a significant additional benefit to WLI, with an improvement in accuracy from 36% to 56% for the cases with m3/sm1 cancers (P < 0.05).

CONCLUSIONS

A well-designed training program can improve the diagnostic accuracy in evaluating cancer invasion depth, with substantial agreement.

Additional chromoendoscopy for colorectal lesions initially diagnosed with low confidence by magnifying narrow-band imaging: Can it improve diagnostic accuracy?

BACKGROUND AND AIM

Magnifying chromoendoscopy has been one of the most reliable diagnostic methods for distinguishing neoplastic from non-neoplastic lesions. The aim of this prospective study was to clarify the clinical usefulness of magnifying chromoendoscopy for colorectal polyps initially diagnosed with low confidence (LC) by magnifying narrow-band imaging (NBI).

METHODS

Consecutive adult patients who underwent total colonoscopic examination with magnifying NBI between July and December 2016 at Sano Hospital were prospectively recruited. Endoscopists were asked to carry out additional magnifying chromoendoscopy for cases that had been initially diagnosed as Japan NBI Expert Team (JNET) Type 1 or 2A with LC by magnifying NBI. We investigated the diagnostic performance of magnifying NBI for polyps diagnosed as JNET Type 1 or 2A with LC (first phase) and that of subsequent magnifying chromoendoscopy (second phase) in differentiating neoplasia from non-neoplasia.

RESULTS

In 50 patients, we analyzed 53 polyps classified as JNET Type 1 or 2A with LC prediction. Accuracy and negative predictive value of magnifying NBI (first phase) were 58.5% (95% CI, 44.1-71.9%) and 66.0% (95% CI, 36.6-77.9%), and those of magnifying chromoendoscopy (second phase) were 66.0% (95% CI, 51.7-78.5%) and 61.1% (95% CI, 43.5-76.9%), respectively.

CONCLUSION

Regardless of the findings of additional chromoendoscopy, all polyps should be resected and submitted for histopathological examination when the confidence level in differentiating adenomatous from hyperplastic polyps by magnifying NBI is low.

Comparative evaluation of new and conventional classifications of magnifying endoscopy with narrow band imaging for invasion depth of superficial esophageal squamous cell carcinoma

A new classification of magnifying endoscopy with narrow band imaging (ME-NBI) for diagnosing and staging superficial esophageal squamous cell carcinoma (SESCC) was proposed by the Japan Esophageal Society in 2011. This study aimed to compare the new classification with the conventional classifications (Inoue's classification and Arima's classification). This was a prospective analysis of data from a single cancer center involving 151 consecutive patients with 156 SESCCs that were endoscopically or surgically resected. Initially, only ME-NBI images were selected and reviewed independently by three experienced endoscopists. White light imaging (WLI) was then evaluated separately after an interval. The diagnostic performance of each classification and interobserver agreement were assessed, and the WLI findings that affect the diagnosis by the new classification were identified. The specificity for classifying invasive depth as epithelium (EP)/lamina propria mucosae (LPM) confined was higher with the new classification than with Inoue's classification (0.512 vs. 0.349; P = 0.02) and Arima's classification (0.512 vs. 0.279; P < 0.01). However, the sensitivity was lower (0.902 vs. 1.000; P < 0.01) compared with Arima's classification. The concordance rates of three evaluators (κ values) were 0.52 for the new classification, 0.50 for Inoue's classification, and 0.23 for Arima's classification. On multivariate analysis, thickness on WLI independently affected the accuracy of diagnosis with the new classification (OR 3.23; 95%CI, 1.30-8.03). The new classification is superior to conventional classifications with respect to specificity for diagnosing SESCC with depth EP/LPM. Thickness on WLI was a factor negatively affecting the diagnostic performance of the new classification.

Vascular density of superficial esophageal squamous cell carcinoma determined by direct observation of resected specimen using narrow band imaging with magnifying endoscopy

Observation of the microvasculature using narrow band imaging (NBI) with magnifying endoscopy is useful for diagnosing superficial squamous cell carcinoma. Increased vascular density is indicative of cancer, but not many studies have reported differences between cancerous and noncancerous areas based on an objective comparison. We observed specimens of endoscopic submucosal dissection (ESD) using NBI magnification, and determined the vascular density of cancerous and noncancerous areas. A total of 25 lesions of esophageal squamous cell carcinoma that were dissected en bloc by ESD between July 2013 and December 2013 were subjected to NBI magnification. We constructed a device that holds an endoscope and precisely controls the movement along the vertical axis in order to observe submerged specimens by NBI magnification. NBI image files of both cancerous (pathologically determined invasion depth, m1/2) and surrounding noncancerous areas were created and subjected to vascular density assessment by two endoscopists who were blinded to clinical information. The invasion depth was m1/2 in 20, m3/sm1 in four and sm2 in one esophageal cancer lesion. Mean vascular density was significantly increased in cancerous areas (37.6 ± 16.3 vessels/mm2) compared with noncancerous areas (17.6 ± 10.0 vessels/mm2) (P < 0.05). The correlation coefficients between vascular density determined by two endoscopists were 0.86 and 0.81 in cancerous and noncancerous areas, respectively. Receiver operating curve (ROC) analysis revealed that the area under the curve (AUC) of vascular density was 0.895 (95% CI, 0.804-0.986). For this ROC curve, sensitivity was 78.3% and specificity was 87.0% when the cutoff value of vascular density was 26 vessels/mm2. NBI magnification confirmed significant increases in vascular density in cancerous areas compared with noncancerous areas in esophageal squamous cell carcinoma. The rates of agreement between vascular density values determined by two independent operators were high.

An early superficial non-ampullary duodenal tumor cured with endoscopic submucosal dissection: A case report

Early superficial non-ampullary duodenal tumors are particularly rare, the clinical manifestations, including typical endoscopic or imaging features, and treatment methods are not well-characterized. The present case report describes a case of an asymptomatic 74-year-old male who presented to the Taizhou People's Hospital (Taizhou, China) for a regular health screening, where a primary superficial non-ampullary duodenal tumor was identified. Upper endoscopy revealed ~1.2 cm lesion in the second portion of the duodenum. Chromoscopy and magnification endoscopy indicated an early cancer characteristic. Subsequent endoscopic submucosal dissection was performed to remove the lesion. Histopathology validated that the lesion was a high-grade intro-epithelial neoplasm without lymph node or blood vessel invasion.

The concept of 'Semi-clean colon' using the pit pattern classification system has the potential to be acceptable in combination with a <3-year surveillance colonoscopy

Histological features of colorectal lesions are currently evaluated via a magnifying chromoendoscopy [pit pattern (PIT) classification]. Advanced histological features are rarely observed in diminutive (≤5 mm) adenomatous polyps (DAPs). The Japanese guidelines indicate that diminutive neoplastic lesions without carcinomatous findings may be left untreated and followed up. At the present institution, DAPs with type IIIL PIT are left untreated in various cases, whereas lesions with type III, IV or V PIT are typically resected via routine colonoscopy. This retrospective study aimed to assess the management of DAPs using PIT classification. The participants of the study included patients <30 years previously referred for an initial colonoscopy, then reobserved for <3 years following the procedure. Participants were classified into three groups: Group A, Patients with type IIIL PIT DAP left untreated (semi-clean colon group); group B, patients with all neoplastic polyps, including DAPs, resected (clean colon group); and group C, patients without any adenomatous polyps (internal control group). The cumulative incidence of the index lesions (ILs) at the follow-up colonoscopy was analysed among the three groups. A total of 4,313 patients were enrolled in the study, with categorization as follows: Group A, 1,246; group B, 1,205; and group C, 1,862 patients. ILs were detected in group A, 100 (8.0%); group B, 104 (8.6%); and group C, 29 (1.6%) patients. There was no significant difference observed between groups A and B. It was verified that removing the type IIIL PIT DAPs did not decrease the incidence of ILs within a 3-year time period. Therefore, these polyps may be left untreated in combination with patient reobservation at an appropriate time interval, potentially one equal to that suggested following a polypectomy.

Cases of primary malignant melanoma and melanocytosis of the esophagus observed by magnifying endoscopy: Application to differential diagnosis: case series

RATIONALE

Primary malignant melanoma of the esophagus (PMME) is a rare disease with an extremely poor prognosis. In contrast, melanocytosis is a benign condition defined as melanocytic proliferation with melanin deposition. PMME is often accompanied by melanocytosis, but differentiating between them is difficult because of their similar appearance.

PATIENT CONCERNS

Here, we reported 3 PMME cases, 2 with melanocytosis.

DIAGNOSES

Magnifying endoscopy revealed characteristic non-uniform pigmented spots along deformed intrapapillary capillary loops (IPCLs) in PMME, while melanocytosis showed fine granule-like or linearly arranged spots and intact IPCLs.

INTERVENTIONS

The patients underwent endoscopic or surgical resection of each lesion.

OUTCOMES

Histologically, magnified images reflected melanocyte growth. For cases 1 and 2, the patients remained disease-free for 61 and 15 months after endoscopic resection, respectively. In case 3, liver metastases developed two months after surgery, and the patient died from liver failure after six months.

LESSONS

This is the first report describing differences in magnified views of the 2 diseases, which aids a differential diagnosis.

Investigation of mucosal pattern of gastric antrum using magnifying narrow-band imaging in patients with chronic atrophic fundic gastritis

BACKGROUND

Magnifying narrow-band imaging (M-NBI) can reportedly help predict the presence and distribution of atrophy and intestinal metaplasia in the gastric corpus. However, the micro-mucosal pattern of the antrum shown by M-NBI differs from that of the corpus. We studied the distribution and histology of the micro-mucosal pattern in the antrum based on magnifying endoscopy.

METHODS

Endoscopic images of the greater curvature of the antrum were evaluated in 50 patients with chronic atrophic fundic gastritis (CAFG). The extent of CAFG was evaluated by autofluorescence imaging. The micro-mucosal pattern was evaluated by M-NBI and classified into groove and white villiform types. The localization of white villiform type mucosa was classified into three types in relation to the areae gastricae: null, central, and segmental types. Biopsies were taken from regions showing different micro-mucosal patterns. Associations among the extent of CAFG, micro-mucosal pattern, and histology were examined.

RESULTS

As the extent of CAFG increased, the proportion of white villiform type mucosa increased, whereas that of groove type mucosa decreased (P=0.022). In patients with extensive CAFG, most of the areae gastricae was composed of the segmental or central type of white villiform type mucosa (P=0.044). The white villiform type mucosa had significantly higher grades of atrophy (P=0.002) and intestinal metaplasia (P<0.001) than did the groove type mucosa.

CONCLUSION

White villiform type mucosa is indicative of atrophy and intestinal metaplasia in the gastric antrum. It extends to the whole or central part of the areae gastricae as CAFG becomes more extensive.

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.

Diagnostic accuracy of endoscopic features of pediatric acute gastrointestinal graft-versus-host disease

BACKGROUND AND AIM

Acute gastrointestinal graft-versus-host disease (GI-GVHD) is a major cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). There are very few studies on specific endoscopic findings in pediatric acute GI-GVHD. The aim of this retrospective case-control study was to elucidate the characteristic endoscopic findings in pediatric acute GI-GVHD that improve the diagnostic accuracy of endoscopy.

METHODS

All consecutive patients under 18 years of age who underwent allogeneic HSCT in Kyoto University Hospital from May 2003 to October 2014 were identified retrospectively. Patients who underwent GI endoscopy as a result of sustained GI symptoms were identified. Intestinal villous patterns were evaluated by magnification endoscopy with the water-immersion technique. The patients were diagnosed with acute GI-GVHD and non-GVHD on the basis of biopsy histology. Endoscopic findings of the two groups were compared.

RESULTS

Of the 171 patients who underwent HSCT, 30 underwent GI endoscopy. Of these, 17 and nine were diagnosed with acute GI-GVHD and non-GVHD, respectively. Compared with non-GVHD, acute GI-GVHD was associated significantly more often with short blunt villi in the duodenum (P = 0.013), variable defect villi and short blunt villi in the ileum (P = 0.009 and 0.035, respectively), and edema, erosion, and tortoiseshell-like mucosae in the colon (P = 0.017, 0.023, and 0.017, respectively).

CONCLUSION

Pediatric acute GI-GVHD was associated with several characteristic features on magnifying endoscopy with the water-immersion technique. These features will be useful for endoscopic diagnosis of pediatric acute GI-GVHD.

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.

Role of magnifying colonoscopy for diagnosis of colorectal neoplasms: From the perspective of Japanese colonoscopists

Colorectal cancer is the third leading cause of cancer-related death. As the therapeutic strategy for colorectal cancer depends on the clinical stage of the tumor, precise and accurate staging is necessary prior to treatment decision-making. Colonoscopy is an essential tool for detection and prevention of colorectal cancer, as it also allows for removal of adenomatous lesions. Using conventional endoscopy, however, it is sometimes difficult to differentiate neoplastic lesions from non-neoplastic lesions. Several new endoscopic technologies have been developed to provide a more precise diagnosis. Magnifying chromoendoscopy and narrow-band imaging endoscopy with or without magnification are invaluable not only for distinction of colorectal neoplastic lesions from non-neoplastic lesions, but also for the accurate diagnosis of invasion depth in colorectal cancers. Based on an accumulation of a large number of clinical data, the use of magnifying colonoscopy has become inevitable for the prediction of histology and the diagnosis of invasion depth of colorectal neoplasms in Japan.

OLGA- and OLGIM-based staging of gastritis using narrow-band imaging magnifying endoscopy

BACKGROUND AND AIM

As atrophic gastritis and intestinal metaplasia as a result of Helicobacter pylori are considered risk factors for gastric cancer, it is important to assess their severity. In the West, the operative link for gastritis assessment (OLGA) and operative link for gastric intestinal metaplasia assessment (OLGIM) staging systems based on biopsy have been widely adopted. In Japan, however, narrow-band imaging (NBI)-magnifying endoscopic diagnosis of gastric mucosal inflammation, atrophy, and intestinal metaplasia has been reported to be fairly accurate. Therefore, we investigated the practicality of NBI-magnifying endoscopy (NBI-ME) for gastritis staging.

METHODS

We enrolled 55 patients, in whom NBI-ME was used to score the lesser curvature of the antrum (antrum) and the lesser curvature of the lower body (corpus). The NBI-ME score classification was established from images obtained beforehand, and then biopsy specimens taken from the observed areas were scored according to histological findings. The NBI-ME and histology scores were then compared. Furthermore, we assessed the NBI-ME and histology stages using a combination of scores for the antrum and corpus, and divided the stages into two risk groups: low and high. The degree to which the stage assessed by NBI-ME approximated that assessed by histology was then ascertained.

RESULTS

Degree of correspondence between the NBI-ME and histology scores was 69.1% for the antrum and 72.7% for the corpus, and that between the high- and low-risk groups was 89.1%.

CONCLUSION

Staging of gastritis using NBI-ME approximates that based on histology, and would be a practical alternative to the latter.

Esophageal carcinoid tumor treated by endoscopic resection

The present report describes a rare case of esophageal carcinoid tumor that was treated by endoscopic resection. A 43-year-old woman underwent esophagogastroduodenoscopy at her family clinic for screening of the upper digestive tract and a small lesion resembling a submucosal tumor was detected in the lower esophagus. A biopsy sample from the lesion was diagnosed as esophageal carcinoid tumor and the patient visited our hospital for detailed examination. The tumor was approximately 3 mm in diameter and its surface appeared to be covered with normal squamous epithelium. The tumor had a shiny reddish surface without ulceration or erosion. Magnifying endoscopy with narrow-band imaging showed structures resembling reticular vessels under the epithelium. Endoscopic ultrasonography depicted the tumor as a low-echoic mass within the lamina propria. Computed tomography did not detect the tumor and no metastatic lesions were evident in other organs. With the patient's informed consent, the tumor was resected using endoscopic submucosal dissection, with a sufficient free margin in both the vertical and horizontal directions. Magnifying endoscopic examination showed the resected tumor to have abundant reticular vessels. Finally, the tumor was diagnosed immunopathologically as an esophageal carcinoid tumor (neuroendocrine cell tumor, grade 1), without lymphatic or vascular invasion.

Endocytoscopic observation of various esophageal lesions at ×600: can nuclear abnormality be recognized?

Endocytoscopy (ECS) is a novel endoscopic technique that allows detailed diagnostic examination of the gastrointestinal tract at the cellular level. We previously reported that use of ECS at ×380 magnification (GIF-Y0002) allowed a pathologist to diagnose esophageal squamous cell carcinoma (ESCC) with high sensitivity (94.9%) but considerably low specificity (46.7%) because this low magnification did not reveal information about nuclear abnormality. In the present study, we used the same magnifying endoscope to observe various esophageal lesions, but employed digital 1.6-fold magnification to achieve an effective magnification of ×600, and evaluated whether this improved the diagnostic accuracy in distinguishing neoplastic from non-neoplastic lesions.We examined the morphology of surface cells using vital staining with toluidine blue and compared the histological features of 40 cases, including 19 case of ESCC and 21 non-neoplastic esophageal lesions (18 cases of esophagitis, 1 case of glycogenic acanthosis, 1 case of leiomyoma, and 1 case of normal squamous epithelium). One endoscopist classified the lesions using the type classification, and we consulted one pathologist for judgment of the ECS images as 'neoplastic', 'borderline', or 'non-neoplastic'. At ×600 magnification, the pathologist confirmed that nuclear abnormality became evident, in addition to the information about nuclear density provided by observation at ×380. The overall sensitivity and specificity with which the endoscopist was able to predict neoplastic lesions using the type classification was 100% (19/19) and 90.5% (19/21), respectively, in comparison with values of 94.7% (18/19 cases) and 76.2% (16/21), respectively, for the pathologist using a magnification of ×600. The pathologist diagnosed two non-neoplastic lesions and one case of ESCC showing an apparent increase of nuclear density with weak nuclear abnormality as 'borderline'. Among the 21 non-cancerous lesions, two cases of esophagitis that were misdiagnosed by the endoscopist were also misinterpreted as 'neoplastic' by the pathologist. We have shown, by consultation with a pathologist, that an ECS magnification of ×600 (on a 19-inch monitor) is adequate for recognition of nuclear abnormality. We consider that it is feasible to diagnose esophageal neoplasms on the basis of ECS images, and that biopsy histology can be omitted if a combination of increased nuclear density and nuclear abnormality is observed.

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.

Dual optical modality endoscopic imaging of cancer development in the mouse colon

BACKGROUND AND OBJECTIVE

We utilize a miniature, dual-modality endoscope that combines fluorescence-based surface magnifying chromoendoscopy (SMC) and optical coherence tomography (OCT) to follow the anatomical changes that occur during adenoma development in the mouse colon.

MATERIALS AND METHODS

Twenty-five mice were treated with the carcinogen azoxymethane (AOM) to induce tumor development in the distal colon, or were treated with saline as control, and were imaged over six months. OCT detects adenoma number with high sensitivity and specificity and can measure lesion size. In methylene blue-lavaged colons, SMC detects changes in the colonic crypts. SMC images of control mouse colons exhibit reticulated patterns of crypts of equal size, forming either a dot or honeycomb pattern.

RESULTS

Images of AOM-treated colons show mild crypt irregularities even in grossly normal tissue. Images of small to medium adenoma exhibit larger crypts, more intense signal, and irregular spacing whereas those of large adenoma have heterogeneous, intense signal and loss of crypt structure.

CONCLUSIONS

The combination of OCT and SMC permits the detection of neoplastic events from the earliest stages of crypt irregularities before gross tissue changes are noted, through to measuring the growth of protruding adenoma.