Accuracy of a scoring system for the differential diagnosis of common gastric subepithelial tumors based on endoscopic ultrasonography

Results of the interim analysis of a prospective, multicenter, observational study of small subepithelial lesions in the stomach

OBJECTIVES

Long-term outcomes of gastric subepithelial lesions have not been elucidated. To reveal the natural history, we initiated a prospective, 10-year follow-up of patients with small (≤20 mm) gastric subepithelial lesions in September 2014. Here, we report the results of an interim analysis of a prospective observational study.

METHODS

In total, 567 patients with 610 lesions were prospectively registered between September 2014 and August 2016. The location, size, morphology, and number of subepithelial lesions were recorded on a web-based case report form. This study has been conducted as an Academic Committee Working Group of the Japan Gastroenterological Endoscopy Society.

RESULTS

The endoscopic follow-up period was 4.60 ± 1.73 years (mean ± standard deviation), and survival data were investigated for 5.28 ± 1.68 years. This interim analysis revealed that the estimated cumulative incidence of a size increase ≥5 mm, after accounting for patients' death and resection of the tumor as competing risk events, was 4.5% at 5 years. In addition, the estimated cumulative incidence of lesion size increase ≥5 mm or resection of lesions was 7.9% at 5 years, and that of size increase ≥10 mm or resection of lesions was 4.5% at 5 years.

CONCLUSION

These results indicate that approximately one in 13 patients with small (≤20 mm) gastric subepithelial lesions may require resection or further investigation for increased tumor size (≥5 mm) within 5 years.

Artificial Intelligence in the Prediction of Gastrointestinal Stromal Tumors on Endoscopic Ultrasonography Images: Development, Validation and Comparison with Endosonographers

Background/Aims

The accuracy of endosonographers in diagnosing gastric subepithelial lesions (SELs) using endoscopic ultrasonography (EUS) is influenced by experience and subjectivity. Artificial intelligence (AI) has achieved remarkable development in this field. This study aimed to develop an AI-based EUS diagnostic model for the diagnosis of SELs, and evaluated its efficacy with external validation.

Methods

We developed the EUS-AI model with ResNeSt50 using EUS images from two hospitals to predict the histopathology of the gastric SELs originating from muscularis propria. The diagnostic performance of the model was also validated using EUS images obtained from four other hospitals.

Results

A total of 2,057 images from 367 patients (375 SELs) were chosen to build the models, and 914 images from 106 patients (108 SELs) were chosen for external validation. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the model for differentiating gastrointestinal stromal tumors (GISTs) and non-GISTs in the external validation sets by images were 82.01%, 68.22%, 86.77%, 59.86%, and 78.12%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in the external validation set by tumors were 83.75%, 71.43%, 89.33%, 60.61%, and 80.56%, respectively. The EUS-AI model showed better performance (especially specificity) than some endosonographers. The model helped improve the sensitivity, specificity, and accuracy of certain endosonographers.

Conclusions

We developed an EUS-AI model to classify gastric SELs originating from muscularis propria into GISTs and non-GISTs with good accuracy. The model may help improve the diagnostic performance of endosonographers. Further work is required to develop a multi-modal EUS-AI system.

Endoscopic ultrasound artificial intelligence-assisted for prediction of gastrointestinal stromal tumors diagnosis: A systematic review and meta-analysis

BACKGROUND

Subepithelial lesions (SELs) are gastrointestinal tumors with heterogeneous malignant potential. Endoscopic ultrasonography (EUS) is the leading method for evaluation, but without histopathological analysis, precise differentiation of SEL risk is limited. Artificial intelligence (AI) is a promising aid for the diagnosis of gastrointestinal lesions in the absence of histopathology.

AIM

To determine the diagnostic accuracy of AI-assisted EUS in diagnosing SELs, especially lesions originating from the muscularis propria layer.

METHODS

Electronic databases including PubMed, EMBASE, and Cochrane Library were searched. Patients of any sex and > 18 years, with SELs assessed by EUS AI-assisted, with previous histopathological diagnosis, and presented sufficient data values which were extracted to construct a 2 × 2 table. The reference standard was histopathology. The primary outcome was the accuracy of AI for gastrointestinal stromal tumor (GIST). Secondary outcomes were AI-assisted EUS diagnosis for GIST vs gastrointestinal leiomyoma (GIL), the diagnostic performance of experienced endoscopists for GIST, and GIST vs GIL. Pooled sensitivity, specificity, positive, and negative predictive values were calculated. The corresponding summary receiver operating characteristic curve and post-test probability were also analyzed.

RESULTS

Eight retrospective studies with a total of 2355 patients and 44154 images were included in this meta-analysis. The AI-assisted EUS for GIST diagnosis showed a sensitivity of 92% [95% confidence interval (CI): 0.89-0.95; P < 0.01), specificity of 80% (95%CI: 0.75-0.85; P < 0.01), and area under the curve (AUC) of 0.949. For diagnosis of GIST vs GIL by AI-assisted EUS, specificity was 90% (95%CI: 0.88-0.95; P = 0.02) and AUC of 0.966. The experienced endoscopists' values were sensitivity of 72% (95%CI: 0.67-0.76; P < 0.01), specificity of 70% (95%CI: 0.64-0.76; P < 0.01), and AUC of 0.777 for GIST. Evaluating GIST vs GIL, the experts achieved a sensitivity of 73% (95%CI: 0.65-0.80; P < 0.01) and an AUC of 0.819.

CONCLUSION

AI-assisted EUS has high diagnostic accuracy for fourth-layer SELs, especially for GIST, demonstrating superiority compared to experienced endoscopists' and improving their diagnostic performance in the absence of invasive procedures.

Endoscopic Ultrasound Advanced Techniques for Diagnosis of Gastrointestinal Stromal Tumours

Gastrointestinal Stromal Tumors (GISTs) are subepithelial lesions (SELs) that commonly develop in the gastrointestinal tract. GISTs, unlike other SELs, can exhibit malignant behavior, so differential diagnosis is critical to the decision-making process. Endoscopic ultrasound (EUS) is considered the most accurate imaging method for diagnosing and differentiating SELs in the gastrointestinal tract by assessing the lesions precisely and evaluating their malignant risk. Due to their overlapping imaging characteristics, endosonographers may have difficulty distinguishing GISTs from other SELs using conventional EUS alone, and the collection of tissue samples from these lesions may be technically challenging. Even though it appears to be less effective in the case of smaller lesions, histology is now the gold standard for achieving a final diagnosis and avoiding unnecessary and invasive treatment for benign SELs. The use of enhanced EUS modalities and elastography has improved the diagnostic ability of EUS. Furthermore, recent advancements in artificial intelligence systems that use EUS images have allowed them to distinguish GISTs from other SELs, thereby improving their diagnostic accuracy.

ACG Clinical Guideline: Diagnosis and Management of Gastrointestinal Subepithelial Lesions

Subepithelial lesions (SEL) of the GI tract represent a mix of benign and potentially malignant entities including tumors, cysts, or extraluminal structures causing extrinsic compression of the gastrointestinal wall. SEL can occur anywhere along the GI tract and are frequently incidental findings encountered during endoscopy or cross-sectional imaging. This clinical guideline of the American College of Gastroenterology was developed using the Grading of Recommendations Assessment, Development, and Evaluation process and is intended to suggest preferable approaches to a typical patient with a SEL based on the currently available published literature. Among the recommendations, we suggest endoscopic ultrasound (EUS) with tissue acquisition to improve diagnostic accuracy in the identification of solid nonlipomatous SEL and EUS fine-needle biopsy alone or EUS fine-needle aspiration with rapid on-site evaluation sampling of solid SEL. There is insufficient evidence to recommend surveillance vs resection of gastric gastrointestinal stromal tumors (GIST) <2 cm in size. Owing to their malignant potential, we suggest resection of gastric GIST >2 cm and all nongastric GIST. When exercising clinical judgment, particularly when statements are conditional suggestions and/or treatments pose significant risks, health-care providers should incorporate this guideline with patient-specific preferences, medical comorbidities, and overall health status to arrive at a patient-centered approach.

Efficacy of ultrasound endoscopy with artificial intelligence for the differential diagnosis of non-gastric gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are common subepithelial lesions (SELs) and require treatment considering their malignant potential. We recently developed an endoscopic ultrasound-based artificial intelligence (EUS-AI) system to differentiate GISTs from non-GISTs in gastric SELs, which were used to train the system. We assessed whether the EUS-AI system designed for diagnosing gastric GISTs could be applied to non-gastric GISTs. Between January 2015 and January 2021, 52 patients with non-gastric SELs (esophagus, n = 15; duodenum, n = 26; colon, n = 11) were enrolled. The ability of EUS-AI to differentiate GISTs from non-GISTs in non-gastric SELs was examined. The accuracy, sensitivity, and specificity of EUS-AI for discriminating GISTs from non-GISTs in non-gastric SELs were 94.4%, 100%, and 86.1%, respectively, with an area under the curve of 0.98 based on the cutoff value set using the Youden index. In the subanalysis, the accuracy, sensitivity, and specificity of EUS-AI were highest in the esophagus (100%, 100%, 100%; duodenum, 96.2%, 100%, 0%; colon, 90.9%, 100%, 0%); the cutoff values were determined using the Youden index or the value determined using stomach cases. The diagnostic accuracy of EUS-AI increased as lesion size increased, regardless of lesion location. EUS-AI based on gastric SELs had good diagnostic ability for non-gastric GISTs.

Application of Endoscopic Ultrasound Combined with Multislice Spiral CT in Diagnosis and Treatment of Patients with Gastrointestinal Eminence Lesions

Objective

To evaluate the application of endoscopic ultrasound (EUS) combined with multislice spiral CT (MSCT) in the diagnosis and treatment of patients with gastric eminence lesions.

Methods

A total of 160 patients with gastric eminence lesions enrolled in our hospital from June 2018 to June 2021 were included and received EUS and MSCT. The results of the two examinations and the postoperative pathological results were compared.

Results

The common pathological types of gastric eminence lesions include polyps and stromal tumors, with the most common sites of lesions in the gastric antrum, followed by the fundus of the stomach and the gastric body. Gastric eminence lesions mostly originate from the mucosal layer and muscularis mucosa, accounting for 83.13% of the total. With pathological results as the gold standard, the detection rate of MSCT was 90.63%, and that of EUS was 78.13%. With the joint diagnosis as a reference, the receiver operating curve (ROC) revealed a higher diagnostic efficiency of MSCT and EUS.

Conclusion

The accuracy of MSCT in the diagnosis of gastric eminence lesions is significantly higher than that of EUS, both of which can offer useful guidance for the choice of endoscopic treatment methods. The combination of MSCT and EUS examination before endoscopic gastroscopy may provide a better treatment efficacy on gastric protruding lesions with high safety.

Differentiating Gastrointestinal Stromal Tumors from Leiomyomas Using a Neural Network Trained on Endoscopic Ultrasonography Images

BACKGROUND

Endoscopic ultrasonography (EUS) is crucial to diagnose and evaluate gastrointestinal mesenchymal tumors (GIMTs). However, EUS-guided biopsy does not always differentiate gastrointestinal stromal tumors (GISTs) from leiomyomas. We evaluated the ability of a convolutional neural network (CNN) to differentiate GISTs from leiomyomas using EUS images. The conventional EUS features of GISTs were also compared with leiomyomas.

PATIENTS AND METHODS

Patients who underwent EUS for evaluation of upper GIMTs between 2010 and 2020 were retrospectively reviewed, and 145 patients (73 women and 72 men; mean age 54.8 ± 13.5 years) with GISTs (n = 109) or leiomyomas (n = 36), confirmed by immunohistochemistry, were included. A total of 978 images collected from 100 patients were used to train and test the CNN system, and 384 images from 45 patients were used for validation. EUS images were also evaluated by an EUS expert for comparison with the CNN system.

RESULTS

The sensitivity, specificity, and accuracy of the CNN system for diagnosis of GIST were 92.0%, 64.3%, and 86.98% for the validation dataset, respectively. In contrast, the sensitivity, specificity, and accuracy of the EUS expert interpretations were 60.5%, 74.3%, and 63.0%, respectively. Concerning EUS features, only higher echogenicity was an independent and significant factor for differentiating GISTs from leiomyomas (p < 0.05).

CONCLUSIONS

The CNN system could diagnose GIMTs with higher accuracy than an EUS expert and could be helpful in differentiating GISTs from leiomyomas. A higher echogenicity may also aid in differentiation.

Diagnostic accuracy of endoscopic ultrasound with artificial intelligence for gastrointestinal stromal tumors: A meta-analysis

OBJECTIVES

Gastrointestinal stromal tumors (GISTs) are thought to have a malignant potential. However, utilizing endoscopic ultrasound (EUS) to differentiate GISTs from other types of subepithelial lesions (SELs) remains challenging. Artificial intelligence (AI)-based diagnostic systems for EUS have been reported to have a promising performance, although the results of the previous studies remain controversial. In this meta-analysis, we aimed to assess the diagnostic accuracy of AI-based EUS in distinguishing GISTs from other SELs.

METHODS

A literature search was conducted on MEDLINE and EMBASE databases to identify relevant articles. The sensitivity, specificity, and area under the summary receiver operating characteristic curve (AUROC) of eligible studies were analyzed.

RESULTS

Seven studies were eligible for the final analysis. The combined sensitivity and specificity of AI-based EUS were 0.93 (95% confidence interval [CI] 0.88-0.96) and 0.78 (95% CI 0.67-0.87), respectively. The overall diagnostic odds ratio of AI-based EUS for GISTs was 36.74 (95% CI 17.69-76.30) with an AUROC of 0.94.

CONCLUSIONS

AI-based EUS showed high diagnostic ability and might help better differentiate GISTs from other SELs. More prospective studies on the diagnosis of GISTs using AI-based EUS are warranted in clinical setting.

Efficiency of an endoscopic resection strategy for management of submucosal tumors < 20 mm in the upper gastrointestinal tract

Background and study aims  The histologic diagnosis of submucosal tumors (SMTs) < 20 mm is challenging. Monitoring is the main option offered, but compliance is debatable. Endoscopic resection (ER) of malignant SMTs or those with an uncertain diagnosis is an alternative that has already been reported about and proposed in our center. The aims of this study were to confirm the safety of this resection strategy and to perform long-term follow-up of malignant SMTs after resection. Patients and methods  All patients who underwent ER for SMTs < 2 cm in a single center between 2007 and 2019 were included retrospectively. Patients were classified into two groups according to the need for postresection follow-up: benign SMTs (B-SMTs) and follow-up SMTs (FU-SMTs). Results  One hundred and one patients were included. The mean tumor size was 16.7 mm. In total, 92 of 101 SMTs had an uncertain diagnosis. Macroscopic resection was completed for 95 SMTs (93.1 %), with en bloc resection in 94 (92.1%). The morbidity rate was 3 %, with no mortality. A total of 84 of 101 SMTs (84 %) were B-SMTs and did not need monitoring, and 17 SMTs (19.7 %) were FU-SMTs (8 gastrointestinal stromal tumors, 6 neuroendocrine tumors, and 3 others). No relapse was reported in the FU-SMT group, with a median follow-up duration of 33 months [4-127] (61 months [17-127] for the gastrointestinal stroma tumor group). Conclusions  The study results suggest ER is a potentially reliable and effective strategy for upper gastrointestinal tract SMTs < 20 mm. Although the strategy needs further validation in advanced care units, it could eliminate the need for long-term monitoring, therefore targeting such follow-up efforts to patients with FU-SMTs.

Predictive Factors for Differentiating Gastrointestinal Stromal Tumors from Leiomyomas Based on Endoscopic Ultrasonography Findings in Patients with Gastric Subepithelial Tumors: A Multicenter Retrospective Study

Background/Aims

The utility of endoscopic ultrasonography (EUS) for differentiating gastrointestinal stromal tumors (GISTs) and leiomyomas of the stomach is not well known. We aimed to evaluate the ability of EUS for differentiating gastric GISTs and leiomyomas.

Methods

We retrospectively reviewed the medical records of patients with histopathologically proven GISTs (n=274) and leiomyomas (n=87). In two consensus meetings, the inter-observer variability in the EUS image analysis was reduced. Using logistic regression analyses, we selected predictive factors and constructed a predictive model and nomogram for differentiating GISTs from leiomyomas. A receiver operating characteristic (ROC) curve analysis was performed to measure the discrimination performance in the development and internal validation sets.

Results

Multivariate analysis identified heterogeneity (odds ratio [OR], 9.48), non-cardia (OR, 19.11), and older age (OR, 1.06) as independent predictors of GISTs. The areas under the ROC curve of the predictive model using age, sex, and four EUS factors (homogeneity, location, anechoic spaces, and dimpling or ulcer) were 0.916 (sensitivity, 0.908; specificity, 0.793) and 0.904 (sensitivity, 0.908; specificity, 0.782) in the development and internal validation sets, respectively.

Conclusions

The predictive model and nomogram using age, sex and homogeneity, tumor location, presence of anechoic spaces, and presence of dimpling or ulcer on EUS may facilitate differentiation between GISTs and leiomyomas.

High-resolution photoacoustic/ultrasound imaging of the porcine stomach wall: an ex vivo feasibility study

Photoacoustic (PA) imaging has become invaluable in preclinical and clinical research. Endoscopic PA imaging in particular has been explored as a noninvasive imaging modality to view vasculature and diagnose cancers in the digestive system. However, these feasibility studies are still limited to rodents or rabbits. Here, we develop a fully synchronized simultaneous ultrasound and photoacoustic microscopy system using two spectral bands (i.e., the visible and near-infrared) in both optical- and acoustic-resolution modes. We investigate the feasibility of imaging gastric vasculature in an ex vivo porcine model. The entire gastric wall, including the mucosa, submucosa, muscularis propria, and serosa, was excised from fresh porcine stomachs immediately followed by ultrasound and PA imaging being performed within a few hours of sacrifice. PA images of the mucosal vasculature were obtained at depths of 1.90 mm, which is a clinically significant accomplishment considering that the average thickness of the human mucosa is 1.26 mm. The layer structure of the stomach wall could be clearly distinguished in the overlaid PA and US images. Because gastric cancer starts from the mucosal surface and infiltrates into the submucosa, PA imaging can cover a clinically relevant depth in early gastric cancer diagnosis. We were able to detect mucosal vasculature in the entire mucosal layer, suggesting the potential utility of combined PA/US imaging in gastroenterology.

Efficacy of Endoscopic Ultrasound Elastography in Differential Diagnosis of Gastrointestinal Stromal Tumor Versus Gastrointestinal Leiomyoma

BACKGROUND The diagnostic efficacy of endoscopic ultrasound (EUS) elastography for alimentary tract diseases remains uncertain. The aim of this study was to evaluate the utility of EUS elastography in differential diagnosis between the 2 most common subepithelium tumors of the digestive tract - gastrointestinal stromal tumors (GISTs) and gastrointestinal leiomyomas (GILs) - which cannot be differentiated by conventional EUS imaging. MATERIAL AND METHODS Electronic records were retrospectively reviewed from Jan 2015 to Jul 2019. Patients accepting EUS elastography with histopathological diagnosis of GISTs or GILs were included. The images of EUS elastography were analyzed by hue histogram in Photoshop. Hue values of RGB, R, G, and B channels of each group were acquired. We used the t test, ROC curve analysis, and binary logistic regression analysis for data post-processing. RESULTS We included 47 patients with GISTs and 14 with GILs. The mean±standard deviations (SD) of hue values were 20.25±0.72, -0.79±0.78, 20.79±1.68, 39.72±1.30 for GISTs and 20.80±0.46, 1.80±1.05, 28.39±2.15, and 31.95±2.60 for GILs of RGB, R, G, and B channels, respectively. The t test showed statistically significant differences in mean hue values between GISTs and GILs in B and G channels, but not in RGB and R channels. The area under the ROC curve combining B and G values was 0.723. Binary logistic regression analysis suggested no statistically significant difference in ability to differentiate between GISTs and GILs with B and G values (P>0.05). CONCLUSIONS There was insufficient evidence to support the application of quantitative EUS elastography for differential diagnosis of GISTs and GILs in this study.

Efficacy of endoscopic ultrasound with artificial intelligence for the diagnosis of gastrointestinal stromal tumors

BACKGROUND

Although endoscopic ultrasound (EUS) is reported to be suitable for determining the layer from which subepithelial lesions (SELs) originate, it is difficult to distinguish gastrointestinal stromal tumor (GIST) from non-GIST using only EUS images. If artificial intelligence (AI) can be used for the diagnosis of SELs, it should provide several benefits, including objectivity, simplicity, and quickness. In this pilot study, we propose an AI diagnostic system for SELs and evaluate its efficacy.

METHODS

Thirty sets each of EUS images with SELs ≥ 20 mm or < 20 mm were prepared for diagnosis by an EUS diagnostic system with AI (EUS-AI) and three EUS experts. The EUS-AI and EUS experts diagnosed the SELs using solely the EUS images. The concordance rates of the EUS-AI and EUS experts' diagnoses were compared with the pathological findings of the SELs.

RESULTS

The accuracy, sensitivity, and specificity for SELs < 20 mm were 86.3, 86.3, and 62.5%, respectively for the EUS-AI, and 73.3, 68.2, and 87.5%, respectively, for the EUS experts. In contrast, accuracy, sensitivity, and specificity for SELs ≥ 20 mm were 90.0, 91.7, and 83.3%, respectively, for the EUS-AI, and 53.3, 50.0, and 83.3%, respectively, for the EUS experts. The area under the curve for the diagnostic yield of the EUS-AI for SELs ≥ 20 mm (0.965) was significantly higher than that (0.684) of the EUS experts (P = 0.007).

CONCLUSION

EUS-AI had a good diagnostic yield for SELs ≥ 20 mm. EUS-AI has potential as a good option for the diagnosis of SELs.

A scoring model for radiologic diagnosis of gastric leiomyomas (GLMs) with contrast-enhanced computed tomography (CE-CT): Differential diagnosis from gastrointestinal stromal tumors (GISTs)

OBJECTIVES

To investigate CT findings and develop a diagnostic score model to differentiate GLMs from GISTs.

METHODS

This retrospective study included 109 patients with pathologically confirmed GLMs (n = 46) and GISTs (n = 63) from January 2013 to August 2018 who received CE-CT before surgery. Demographic and radiological features was collected, including lesion location, contour, presence or absence of intralesional necrosis and ulceration, growth pattern, whether the tumor involved EGJ, the long diameter (LD) /the short diameter (SD) ratio, pattern and degree of lesion enhancement. Univariate analyses and multivariate logistic regression analyses were performed to identify independent predictors and establish a predictive model. Independent predictors for GLMs were weighted with scores based on regression coefficients. A receiver operating characteristic (ROC) curve was created to determine the diagnostic ability of the model. Overall score distribution was divided into four groups to show differentiating probability of GLMs from GISTs.

RESULTS

Five CT features were the independent predictors for GLMs diagnosis in multivariate logistic regression analysis, including esophagogastric junction (EGJ) involvement (OR, 367.9; 95 % CI, 5.8-23302.8; P =  0.005), absence of necrosis (OR, 11.9; 95 % CI, 1.0-138. 1; P =  0.048) and ulceration (OR, 151.9; 95 % CI, 1.4-16899.6; P =  0.037), degree of enhancement (OR, 9.3; 95 % CI, 3.2-27.4; P <  0.001), and long diameter/ short diameter (LD/SD) ratio (OR,170.9; 95 % CI, 8.4-3493.4; P =  0.001). At a cutoff of 9 points, AUC for this score model was 0.95, with 95.65 % sensitivity, 79.37 % specificity, 77.19 % PPV, 96.15 % NPV and 86.24 % diagnostic accuracy. An increasing trend was showed in diagnostic probability of GLMs among four groups based on the score (P <  0.001).

CONCLUSIONS

The newly designed scoring system is reliable and easy-to-use for GLMs diagnosis by distinguishing from GISTs, including EGJ involvement, absence of ulceration and necrosis, mild enhancement and high LD/SD ratio. The overall score of model ranged from 1 to 17 points, which was divided into 4 groups: 1-7 points, 7-10 points, 10-13 points and 13-17 points, with a diagnostic probability of GLMs 0%, 45 %, 83 % and 100 %, respectively.

Evaluation of Upper Endoscopic and Endoscopic Ultrasound Features in the Differential Diagnosis of Gastrointestinal Stromal Tumors and Leiomyomas in the Upper Gastrointestinal Tract

Background

Differentiation between benign and malignant subepithelial lesions (SELs) in the upper gastrointestinal tract (UGT) leads to far-reaching clinical consequences. An accurate diagnosis can be challenging because of the insufficient diagnostic yield of upper endoscopy, endoscopic ultrasound (EUS), and different types of biopsy.

Aim

Our aim was to reveal the efficacy of upper endoscopic and EUS features for the differential diagnosis of hypoechogenic SELs (gastrointestinal stromal tumors [GISTs] and leiomyomas) in the UGT.

Materials and Methods

The research covers a case series study of 27 hypoechogenic SELs in the UGT between 2012 and 2015 at Vilnius University Hospital Santaros Klinikos. Upper endoscopic and EUS features of SELs were recorded. In order to standardize the diagnostic approach to GISTs and leiomyomas, we assigned scores for seven upper endoscopic and EUS features.

Results

The mean total scores in the GIST group were significantly higher than those in the leiomyoma group: 3.25 ± 1.71 and 0.53 ± 0.83 (p < 0.0001), respectively. Increment by one score increased the odds ratio for GIST 5.87 times (95% CI 1.63-21.11; p = 0.007). The total score demonstrated very good discriminatory features of GISTs against leiomyomas (area under the receiver operating characteristic curve 0.94 [0.86-1]). The cutoff value of 1.5 total score indicated 83.3% sensitivity and 93.3% specificity in diagnosing GISTs.

Conclusions

Upper endoscopy and EUS are useful methods in making a definite diagnosis of SELs. Their diagnostic accuracy for the differential diagnosis of GISTs and leiomyomas is sufficient.

Diagnosing Gastric Mesenchymal Tumors by Digital Endoscopic Ultrasonography Image Analysis

Gastric mesenchymal tumors (GMTs) are incidentally discovered in national gastric screening programs in Korea. Endoscopic ultrasonography (EUS) is the most useful diagnostic modality for evaluating GMTs. The differentiation of gastrointestinal stromal tumors from benign mesenchymal tumors, such as schwannomas or leiomyomas, is important to ensure appropriate clinical management. However, this is difficult and operator dependent because of the subjective interpretation of EUS images. Digital image analysis computes the distribution and spatial variation of pixels using texture analysis to extract useful data, enabling the objective analysis of EUS images and decreasing interobserver and intraobserver agreement in EUS image interpretation. This review aimed to summarize the usefulness and future of digital EUS image analysis for GMTs based on published reports and our experience.

Value of CT Imaging in the Differentiation of Gastric Leiomyoma From Gastric Stromal Tumor

Purpose:

To discuss significant computed tomography (CT) findings that differentiate gastric leiomyomas (GLs) from small gastric stromal tumors (GSTs).

Methods:

One hundred sixty cases with pathologically proven GLs (n = 50) and GSTs (n = 110) with comprehensive CT images were enrolled in this retrospective study. Computed tomography findings (ie, size, location, contour, growth pattern, enhancement degree, necrosis, ulceration, calcification, and lymph nodes) were analyzed through the χ2 or Fisher exact test, independent T test, and multivariate (logistic regression) analysis. Sensitivity and specificity were also calculated.

Results:

Features of cardia location, endophytic growth, homogeneous gradual enhancement, absent of necrosis, long diameter less than 24 mm, short diameter less than 20 mm, unenhanced CT value larger than 35.2 Hounsfield units (HU), portal venous phase CT value larger than 67.4 HU, and enhancement degree of arterial and venous phase less than 16.2 HU and 32.4 HU were found to be statistically significant between GLs and small GSTs ( P < .05). On multivariate analysis, cardia location, endophytic growth, and homogeneous gradual enhancement were independent predictive factors for GLs and small GSTs.

Conclusion:

These 10 CT criteria are very helpful to differentiate GLs from small GSTs. Especially cardia location, endophytic growth, and homogeneous gradual enhancement are of high value in differential diagnosis.

Contrast Enhanced Endoscopic Ultrasound Imaging for Gastrointestinal Subepithelial Tumors

Subepithelial tumors are divided into benign subepithelial and potentially malignant gastrointestinal stromal tumors. It is difficult to distinguish between these tumor types. Contrast-enhanced harmonic endoscopic ultrasound is reportedly useful for diagnosing subepithelial tumors, can be safely and easily performed by understanding the principle and method, and can be used to distinguish between tumor types with high sensitivity on the basis of differences in contrast effect. The generated image shows a hyperenhancement pattern in gastrointestinal stromal tumors (sensitivity, 78%-100%; specificity, 60%-100%; accuracy, 60%-100%) and hypoenhancement pattern in benign subepithelial tumors. Contrast-enhanced harmonic endoscopic ultrasound can be used to estimate the malignancy potential of gastrointestinal stromal tumors by evaluating the uniformity of the contrast and the blood vessels inside the tumor, with abnormal intra-tumor blood vessels, heterogeneous enhancement, and non-enhancing spots suggesting malignancy. Contrast-enhanced harmonic endoscopic ultrasound has a higher sensitivity than other imaging modalities for the detection of vascularity within gastrointestinal stromal tumors. Additionally, it has been reported that treatment effects can be estimated by evaluating the blood flow in the gastrointestinal stromal tumor before and after treatment with tyrosine kinase inhibitors using contrastenhanced ultrasound. However, there will be subjective-bias and the results depends on the performer's skill.

Comparison of the Diagnostic Ability of Endoscopic Ultrasonography and Abdominopelvic Computed Tomography in the Diagnosis of Gastric Subepithelial Tumors

Background/Aims

Endoscopic ultrasonography (EUS) is the most efficient imaging modality for gastric subepithelial tumors (SETs). However, abdominopelvic computed tomography (APCT) has other advantages in evaluating the characteristics, local extension, or invasion of SETs to adjacent organs. This study aimed to compare the diagnostic ability of EUS and APCT based on surgical histopathology results.

Methods

We retrospectively reviewed data from 53 patients who underwent both EUS and APCT before laparoscopic wedge resection for gastric SETs from January 2010 to December 2017 at a single institution. On the basis of histopathology results, we assessed the diagnostic ability of the 2 tests.

Results

The overall accuracy of EUS and APCT was 64.2% and 50.9%, respectively. In particular, the accuracy of EUS vs. APCT for the diagnosis of gastrointestinal stromal tumors (GISTs), leiomyomas, and ectopic pancreas was 83.9% vs. 74.2%, 37.5% vs. 0.0%, and 57.1% vs. 14.3%, respectively. Most of the incorrect diagnoses with EUS involved hypoechoic lesions originating in the fourth echolayer, with the most common misdiagnosed lesions being GISTs mistaken for leiomyomas and vice versa.

Conclusions

APCT showed a lower overall accuracy than EUS; however, APCT remains a useful modality for malignant/potentially malignant gastric SETs.

A Novel Method of Diagnosing Aberrant Pancreas: Needle-based Confocal Laser Endomicroscopy

Aberrant pancreas is defined as pancreatic tissue present outside of the pancreas and is often found incidentally during esophagogastroduodenoscopy. Obtaining sufficient tissue to differentiate aberrant pancreas from other subepithelial lesions is sometimes difficult. Due to the lack of a definitive diagnosis, patients often undergo unnecessary surgery. We herein report the first case of aberrant pancreas in which the concomitant use of needle-based probe confocal laser endomicroscopy and fine-needle aspiration supported the final diagnosis. Needle-based probe confocal laser endomicroscopy provides a real-time in vivo histopathology evaluation and may be a feasible means of diagnosing aberrant pancreas.

Gastric heterotopic pancreas and stromal tumors smaller than 3 cm in diameter: clinical and computed tomography findings

BACKGROUND

Identifying gastric heterotopic pancreas and stromal tumors is difficult. Few studies have reported computed tomography (CT) findings for differentiating lesions less than 3 cm in diameter. In this study, we aimed to identify clinical characteristics and CT findings that can differentiate gastric heterotopic pancreatic lesions from stromal tumors less than 3 cm in diameter.

METHODS

A total of 132 patients with pathologically confirmed gastric heterotopic pancreas (n = 66) and stromal tumors (n = 66) were included. Each group was divided into primary (n = 50) and validation cohort (n = 16). Clinical characteristics and CT findings were retrospectively reviewed. CT findings included location, border, contour, growth pattern, enhancement pattern and grade, the enhancement value of tumor, enhancement ratio of tumor, and enhancement ratio of tumor to pancreas in venous phase. The findings in the two groups were compared using the Pearson χ² test or Student t-test. Receiver operating characteristic curves were used to determine areas under the curve and optimal cut-offs.

RESULTS

Significant differences were observed between heterotopic pancreas and stromal tumors in the distribution of tumor location, border, contour (all P < 0.001), enhancement values (P < 0.001), enhancement ratios of tumors (P < 0.001), and enhancement ratios of tumors to pancreas (P < 0.001). No significant differences existed in growth pattern (P = 0.203). The area under the curve differed significantly between enhancement ratio of tumor to pancreas and enhancement ratio (P = 0.030). There were significant differences in above characteristics between two groups in validation cohort.

CONCLUSIONS

Heterotopic pancreas has characteristic CT features differentiating it from stromal tumors.

Ectopic pancreas in the upper gastrointestinal tract: Is endosonographic diagnosis reliable? Data from the German Endoscopic Ultrasound Registry and review of the literature

Background:

Ectopic pancreas (EP) belongs to the most frequent subepithelial lesions (SELs) of the upper gastrointestinal (GI) tract. In the majority of cases, it is detected incidentally. Differential diagnosis from mesenchymal subepithelial tumors may be difficult.

Methods:

Among 24,308 endosonographic examinations and interventions, which were prospectively enrolled in the database of the German Endoscopic Ultrasound (EUS) Registry from January 2009 to August 2013, 575 were performed for suspected SELs of the upper GI tract. Sixty three cases of EP of the upper GI tract (stomach, n = 53; duodenum, n = 10; esophagus, n = 0) were extracted and retrospectively reviewed.

Results:

In 65.1% of cases, radial echoendoscopes or radial miniprobes were used for examination. Nearly 84% of EP was found in the stomach, 16% in the duodenum, none in the esophagus. In 88.9% of cases, the EUS examination discerned the layer of origin. In 59% of cases EP was described as a heterogeneous, in 28.6% as a homogeneous-hypoechoic and in 7.9% as a homogeneous-echogenic subepithelial mass lesion. Mean diameter was 13.0 mm × 8.1 mm, the mean ratio between long and short axis diameter was 1.75. EUS-guided fine needle aspiration (EUS-FNA) was used to accomplish cytological or histological diagnosis in only 6.3% of cases.

Conclusions:

EP accounts for 11% of all EUS examinations performed for subepithelial lesions of the upper GI tract and prospectively enrolled in the German EUS registry. Rather than being an eyecatcher, EP is a chameleon with numerous differential diagnoses. In selected cases, EUS-FNA may help clarifying the diagnosis.

Oval mucosal opening bloc biopsy after incision and widening by ring thread traction for submucosal tumor

Gastric submucosal tumors (SMTs) less than 2 cm are generally considered benign neoplasms, and endoscopic observation is recommended, but SMTs over 2 cm, 40% of which are gastrointestinal stromal tumors (GISTs), have malignant potential. Although the Japanese Guidelines for GIST recommend partial surgical resection for GIST over 2 cm with malignant potential as well as en bloc large tissue sample to obtain appropriate and large specimens of SMTs, several reports have been published on tissue sampling of SMTs, such as with endoscopic ultrasound sound fine needle aspiration, submucosal tunneling bloc biopsy, and the combination of bite biopsy and endoscopic mucosal resection. Because a simpler, more accurate method is needed for appropriate treatment, we developed oval mucosal opening bloc biopsy after incision and widening by ring thread traction for submucosal tumor (OMOB) approach. OMOB was simple and enabled us to obtain large samples under direct procedure view as well as allowed us to restore to original mucosa.

Endoscopic ultrasonography diagnosis of subepithelial lesions

Using endoscopic ultrasonography (EUS), it is practicable to diagnose subepithelial lesions (SEL) with originating layer, echo level, and internal echo pattern etc. Lipoma, lymphangioma, and cyst have characteristic features; therefore, there is no need for endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Ectopic pancreas and glomus tumors, which originate from the third and fourth layers, are frequently seen in the antrum. However, ectopic pancreas located in the fundus or body is large and originates from the third and fourth layers (thickening of fourth layer). Each subepithelial lesion has characteristic findings. However, imaging differentiation of tumors originating from the fourth layer is very difficult, even if contrast echo is used. Therefore, EUS-FNA should be done in these tumors, but the diagnostic yield for small lesions is not sufficient for clinical demands. Generally, those tumors, including small ones, should be first followed up in 6 months, then yearly follow up in cases of no significant change in size and features. When those tumors become larger than 1-2 cm, EUS-FNA is recommended. Furthermore, unusual SEL and SEL with malignant findings such as nodular, heterogeneous, anechoic area, and ulceration indicate EUS-FNA. Cap-attached forward-viewing echoendoscope is very helpful for EUS-FNA of small SEL.

Subepithelial rectal gastrointestinal stromal tumor - the use of endoscopic ultrasound-guided fine needle aspiration to establish a definitive cytological diagnosis: a case report

Background

Gastrointestinal stromal tumors are the most common mesenchymal neoplasms affecting the gastrointestinal tract. The stomach is the most common location to be affected, and the rectum one of the rarest, but the whole gastrointestinal tract remains susceptible. Gastrointestinal stromal tumors account for only 0.1% of rectal tumors. Currently, endoscopic ultrasound plays an essential role in the diagnostic process of gastrointestinal stromal tumors, especially when the affected sites have a worse outcome and higher morbidity rates.

Case presentation

We describe the case of a 68-year-old white Japanese man with a history of long-term mild rectal pain and tenesmus. A digital rectal examination revealed a right palpable solid mass ranging from 3 to 7 cm from his anal verge. A colonoscopy was performed and showed a 5 cm elevated lesion covered by normal mucosa, located 4 cm above the pectineal line. Endoscopic ultrasound confirmed the diagnosis of a homogeneous hypoechoic mass with areas of necrosis as a rectal subepithelial lesion originating at the fourth layer (muscularis propria). He then underwent endoscopic ultrasound-guided fine needle aspiration of the lesion, followed by cytological and immunohistochemistry evaluation. The evaluation showed spindle and epithelioid cells of variable sizes, in fascicles separated by stroma, which reacted firmly and consistently to CD117/c-kit and CD34, and negative to desmin and S-100 protein. There was weak staining for nuclear Ki-67 in the tumor cells. A diagnosis of rectal gastrointestinal stromal tumor was confirmed. After a multidisciplinary meeting, an abdominoperineal resection of his rectum was performed. The pathology of the specimen confirmed the diagnosis of rectal gastrointestinal stromal tumor. He is now asymptomatic after 3 months’ follow-up and is on adjuvant therapy with a tyrosine-kinase inhibitor.

Conclusions

Gastrointestinal stromal tumors are rare tumors, and among the variety of primary location sites, the rectum is one of the rarest. The localization of this type of tumor has worse outcomes and higher morbidity rates. We report this rare case to emphasize the need for precise diagnosis and the important role of endoscopic ultrasound-guided fine needle aspiration in such situations.

Contrast-enhanced (endoscopic) ultrasound and endoscopic ultrasound elastography in gastrointestinal stromal tumors

Background and Objectives:

Gastrointestinal stromal tumors (GISTs) represent the largest group of subepithelial tumors (SET) of the upper gastrointestinal (GI) tract. They may show malignant behavior, in contrast to other SET. Endoscopic ultrasound (EUS) is frequently used to characterize SET. With the introduction of contrast-enhanced ultrasound (CEUS) into EUS (CE-EUS), distinct enhancement patterns can be detected. In the presented study, the characteristic features of CE-EUS in GIST are analyzed and compared with those of other SET.

Materials and Methods:

Consecutive patients from four centers with SET of the upper and middle GI tract were included and received endoscopic or transcutaneous CEUS. The results were compared with EUS-guided tissue acquisition, forceps biopsy, or surgical resection.

Results:

Forty-two out of 62 (68%) patients had SET of the stomach, 17/62 (27%) of the small intestine, 2/62 (3%) of the esophagus, and 1/62 (2%) extraintestinal. Eighty-one percent underwent surgery. Leiomyoma was found in 5/62 (8%) and GIST in 57/62 patients (92%). Thirty-nine out of 57 (68%) patients had GIST lesions in the stomach, 17/57 (30%) had GIST of the small intestine, and 1/57 (2%) patients had extraintestinal GISTs. GIST size was 62.6 ± 42.1 (16–200) mm. Hyperenhancement had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 98%, 100%, 100%, 93%, and 98% for the diagnosis of GIST. Fifty out of 57 patients with GIST (88%) showed avascular areas in the center of the lesions.

Conclusion:

CE-EUS and CEUS show hyperenhancement and avascular areas in a high percentage of GIST but not in leiomyoma. Thus, GIST and leiomyoma can be discriminated accurately.

Submucosal Tunneling Endoscopic Resection of a Leiomyoma Originating from the Muscularis Propria of the Gastric Cardia (with Video)

While endoscopic submucosal dissection (ESD) is widely used to treat gastrointestinal tumors, it is rarely used for subepithelial tumors (SETs) originating from the muscularis propria of the esophagus and gastric cardia because of the risk of perforation and problems with inadequate space and field of view during procedures. Submucosal tunneling endoscopic resection (STER) is a new therapeutic method for treating SETs in specific locations in the esophagus and stomach. This technique is highly skill-dependent, using a mucosal flap that covers a deeper part of the gut wall, but is safe and minimally invasive compared with conventional endoscopic approaches such as ESD in SETs originating from the muscularis propria.We report a patient who underwent STER to remove a SET located at the gastric cardia. The patient recovered without any complications. We believe that our case shows the efficacy and safety of the STER technique for patients with a SET originating from the muscularis propria.

Role of Endoscopic Ultrasonography in Guiding Treatment Plans for Upper Gastrointestinal Subepithelial Tumors

Gastrointestinal (GI) subepithelial tumors (SETs) are usually observed incidentally by endoscopy and have diverse prognoses, varying from benign to potentially malignant. When a GI SET is suspected, endoscopic ultrasonography (EUS) is the most accurate diagnostic method to differentiate it from extraluminal compression. To determine the nature of GI SETs, EUS is also the most accurate diagnostic method, and reveals the precise sonographic nature of the lesion. There are some SETs with typical EUS findings of GI SETs, but most hypoechoic lesions are difficult to diagnose based on EUS images alone. EUS is also helpful to determine GI wall involvement in SETs and optimal treatment methods. For the diagnosis of GI SETs, obtaining a proper specimen is essential. EUS-guided cytology or biopsy methods such as fine-needle aspiration, Tru-Cut biopsy, and the newly introduced fine-needle biopsy (FNB) provide good results. To increase the diagnostic yield for GI SETs, cytology with immunocytochemical staining is used for cytological interpretation, resulting in good diagnostic yields. Recently, EUS-FNB using cheese slicer technology has been introduced, and has been reported to provide good diagnostic results for GI SETs.

Diagnostic potential of endoscopic ultrasonography-elastography for gastric submucosal tumors: A pilot study

BACKGROUND AND AIM

Qualitative diagnosis for gastric submucosal tumors (SMT) is not easy. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in combination with EUS-elastography (EUS-EG) is reported useful for qualitatively diagnosing pancreatic tissues. We prospectively studied whether EUS-EG could be useful in qualitative diagnosis of gastric SMT.

METHODS

We prospectively registered 25 consecutive patients with gastric SMT diagnosed by esophagogastroduodenoscopy and carried out qualitative evaluations using EUS-EG (May 2013 to March 2015) followed by histopathological diagnosis using EUS-FNA or endoscopic mucosal cutting biopsy. Elastic scores of gastric SMT were compared to the cytological diagnosis.

RESULTS

Of 25 patients, 22 had a confirmed cytological diagnosis. Regarding the Giovannini elastic score, of three patients with aberrant pancreas, one was score 1 and two were score 2; of eight patients with leiomyoma, seven were score 2 and one was score 3. Both of two patients with schwannoma were score 4. Of nine patients with gastrointestinal stromal tumor, six were score 4 and three were score 5. Gastrointestinal stromal tumor (GIST) is harder than other types of gastric SMT, and our study's findings suggested the usefulness of EUS-EG, which can also assess tumor hardness of gastric SMT.

CONCLUSION

EUS-EG might be helpful for the differential diagnosis of gastric SMT, especially to differentiate GIST from other SMT.

Therapy and follow-up of upper gastrointestinal subepithelial lesions

AIM: To explore the nature, growth, and malignant transformation of upper gastrointestinal submucosal lesions (SMLs), and evaluate the clinical efficacy, necessity and safety of surgery or endoscopic therapy for SMLs.

METHODS: We retrospectively collected 1915 cases of upper gastrointestinal submucous lesions, which were evaluated by endoscopic ultrasonography from January 2014 to December 2014 at our department. This diagnostic modality provided features about lesion location (esophagus and stomach), size, echo performance, layer of origin, etc. Different therapeutic methods were chosen according to the size, origin, and location of SMLs as well as patient's preferences. Clinical treatments included follow-up, endoscopic therapy (endoscopic snare resection, endoscopic resection, endoscopic submucosal resection, endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), submucosal tunneling endoscopic resection, etc.), and surgery (open surgery, laparoscopy, and thoracoscopy). Endoscopic or surgical treatment of SMLs was performed when lesion size was significantly increased or suspected to have malignant transformation. Successful cases, size of the mass and layer of origin (mucosa layer, muscularis mucosa layer, submucosa layer, and serosal layer), complications (bleeding, perforation) and conversion surgery or not were recorded.

RESULTS: In 1135 cases followed by EUS, median age was 50.7 years ± 10.3 years (range, 19-78 years), and male/female ratio was 1.16. There were 687 esophageal SMLs and 448 gastric SMLs followed by regular endoscopy (range, 3-60 mo). Esophageal cases at initial measurement had a mean size of 0.82 cm ± 0.24 cm, and gastric cases had an initial mean size of 1.31 cm ± 0.44 cm. Of the followed cases of esophagus SMLs, 18 showed an obviously increased size (>2 cm), including 5 significantly increased cases (>3 cm) over a period of 6 mo and 13 moderately increased cases (>2 cm and <3 cm) during 12 mo. Surgical resection was performed in 5 lesions ≥3 cm in size, which were diagnosed as benign lesions in 3 (one leiomyoma and two cysts) and malignant lesions in 2 (1 leiomyosarcoma and 1 malignant granular cell tumor). Of the followed cases of gastric SMLs, 16 had an obviously increased size (>2 cm), including 10 significantly increased cases (>3 cm). Traditional surgery and endoscopic therapy were performed in 10 lesions ≥3 cm in size, which were diagnosed as gastrointestinal stromal tumors (GISTs) in 8 and leiomyomas in 2. A total of 780 cases underwent endoscopic or surgical therapy. Of 112 cases (19 esophageal cases and 93 gastric cases) treated by surgery, 2 (GIST and leiomyosarcoma) developed delayed bleeding, and the success rate of surgical treatment was 98.2%. Of 668 cases who underwent endoscopic therapy, 6 (4 in ESE group and 2 in ESD group) ended up with perforation and 4 of them (4 in ESE group) were converted to surgery; 2 (both in ESE group) developed intraoperative bleeding, which was managed by endoscopic spraying of drugs, electric coagulation and clips to achieve hemostasis; 2 cases in ESE group had failed dissection and then followed by EUS. The success rate of endoscopic therapy was 98.5%. Of 431 esophageal SMLs, there were 371 (86.08%) leiomyomas, 21 (4.87%) GISTs, and 13 (3.02%) cysts. Of 349 gastric SMLs, there were 168 (48.13%) GISTs, 87 (24.92%) leiomyomas, and 60 (17.91%) cases of ectopic pancreas.

CONCLUSION: No matter where the lesion is located, the esophagus or stomach, lesion size significantly increased over a period of 6 mo after initial measurement. However, few further change were observed in size, shape and EUS finding such as echo pattern or regularity of the outer margin over a period of 6-60 mo. Leiomyoma is the most common gastrointestinal SML in the esophagus, while GISTs are common in the stomach. Leiomyoma lesions rarely showed significant change as shown by endoscopic examination. Excessive medical therapy involves known issues associated with cost-effectiveness, patient compliance and risk of complications, and conservative treatment with regular clinical follow-up is recommended.

Efficiency and safety of endoscopic resection in the management of subepithelial lesions of the stomach

BACKGROUND

Gastric subepithelial tumors represent a diagnostic and therapeutic challenge, given their histologic heterogeneity and potential malignant behavior.

OBJECTIVE

The objective of this article is to evaluate the interest, efficiency and safety of endoscopic resection for subepithelial gastric lesions of size <20 mm.

METHODS

We conducted a single-center retrospective study in a tertiary care center.

RESULTS

A total of 33 lesions (10 malignant/23 benign lesions) were studied. Mean histological size was 14.5 mm. Nine EMR, 18 ESD and six hybrid resections were performed. A total of 93.9% lesions were resected in one piece. At six months' follow-up, complete and definitive resection was obtained in 96.7% of cases. A vertical resection was insufficient in four cases. One GIST needed a complementary surgical resection, one neuroendocrine tumor was successfully treated by a new ESD session and two pancreatic rests were not additionally treated given the benign character and the absence of residual tissue in endoscopic control after six months. There was only one severe adverse event (2.9%); one pneumoperitoneum with ESD, three bleeding with one ESD and two EMR, always treated conservatively or endoscopically.

CONCLUSION

Endoscopic resection is safe and should be the procedure of choice for both diagnosis and definitive resection of subepithelial gastric lesions of size under 20 mm.

Endoscopic resection of submucosal tumors

Submucosal gastrointestinal tumors represent a unique, diverse and challenging group of lesions found in modern medical practice. While management has traditionally been surgical, the development of advanced endoscopic techniques is challenging this approach. This review aims to investigate the role of endotherapy in treatment pathways, with a focus on carcinoid and gastrointestinal stromal tumors. In particular, we will discuss which lesions can be safely treated endoscopically, the evidence base behind such approaches and the limitations of the current evidence. The review will consider how these techniques may change the management of submucosal tumors in the future.

Current status of endoscopic ultrasound for the upper gastrointestinal tract in Asia

We summarize the current status of endoscopic ultrasound (EUS) for the upper gastrointestinal (GI) tract solely in Asia, focusing on the staging of superficial cancers and the diagnosis of submucosal tumors (SMT), by analysis of questionnaire responses and a literature review. EUS for assessing the depth of superficial cancers of the upper GI tract is useful; however, evidence is lacking to support that EUS is superior to other modalities. The current status of EUS varies across different Asian countries, and standardization of the methods used both during the procedure and for depth subclassification is necessary to evaluate the diagnostic accuracy. Although EUS alone is limited in the diagnosis of SMT, EUS-guided fine-needle aspiration is an effective and safe diagnostic tool. Although there is a role for EUS, there are still many limitations both technically and in terms of accessibility.