Endoscopic ultrasonography for gastric submucosal lesions

Factors Associated with Clinically Significant Extrinsic Compression on Gastroduodenal Endoscopy

BACKGROUND

Although clinicians frequently encounter incidentally detected gastroduodenal extrinsic compressive lesions (GDECLs) on upper gastrointestinal endoscopy (UGE), the optimal management approach for GDECLs has not been fully established. This study aimed to stratify and identify important factors associated with clinically significant GDECLs that require regular follow-up or further treatment.

METHODS

Between June 2007 and December 2015, a total of 73 patients with suspected GDECLs on UGE at Kyung Hee University Hospital at Gangdong were identified and studied retrospectively. After the final diagnosis, patients were divided into the following two groups: clinically significant GDECLs, which requires regular follow-up or further treatment, and clinically non-significant GDECLs.

RESULTS

Among 73 GDECLs, 23 (31.5%) lesions were classified as clinically significant GDECLs and 50 (68.5%) as clinically non-significant GDECLs. In multivariate analysis, clinical and endoscopic parameters that were independently associated with clinically significant GDECLs included older age (≥ 60 years), large size (≥ 4 cm) of extrinsic compression, previous history of intra-abdominal malignancy, and symptoms of abdominal distension (all p < 0.05).

CONCLUSIONS

Several clinical and endoscopic parameters showed significant association with the identification of clinically significant GDECLs on endoscopy. These predictive factors might be useful in determining whether to perform further diagnostic work-up in patients with GDECLs.

Endoscopic Ultrasound and Gastric Sub-Epithelial Lesions: Ultrasonographic Features, Tissue Acquisition Strategies, and Therapeutic Management

Background and objectives: Subepithelial lesions (SELs) of the gastrointestinal (GI) tract present a diagnostic challenge due to their heterogeneous nature and varied clinical manifestations. Usually, SELs are small and asymptomatic; generally discovered during routine endoscopy or radiological examinations. Currently, endoscopic ultrasound (EUS) is the best tool to characterize gastric SELs. Materials and methods: For this review, the research and the study selection were conducted using the PubMed database. Articles in English language were reviewed from August 2019 to July 2024. Results: This review aims to summarize the international literature to examine and illustrate the progress in the last five years of endosonographic diagnostics and treatment of gastric SELs. Conclusions: Endoscopic ultrasound is the preferred option for the diagnosis of sub-epithelial lesions. In most of the cases, EUS-guided tissue sampling is mandatory; however, ancillary techniques (elastography, CEH-EUS, AI) may help in both diagnosis and prognostic assessment.

Clinical course of asymptomatic duodenal subepithelial lesions

BACKGROUND/AIMS

There is limited knowledge regarding the management of duodenal subepithelial lesions (SELs) owing to a lack of understanding of their natural course. This study aimed to assess the natural course of asymptomatic duodenal SELs and provide management recommendations.

METHODS

Patients diagnosed with duodenal SELs and followed up for a minimum of 6 months were retrospectively investigated.

RESULTS

Among the 443,533 patients who underwent esophagogastroduodenoscopy between 2008 and 2020, duodenal SELs were identified in 0.39% (1,713 patients). Among them, 396 duodenal SELs were monitored for a median period of 72.5 months (interquartile range, 37.7-111.3 mo). Of them, 16 SELs (4.0%) showed substantial changes in size or morphology at a median follow-up of 35.1 months (interquartile range, 21.7-51.4 mo). Of these SELs with substantial changes, tissues of two SELs were acquired using endoscopic ultrasound-guided fine needle aspiration biopsy: one was a lipoma and the other was non-diagnostic. Three SELs were surgically or endoscopically removed; two were diagnosed as gastrointestinal stromal tumors, and one was a lipoma. An initial size of 20 mm or larger was associated with substantial changes during follow-up (p = 0.016).

CONCLUSION

While the majority of duodenal SELs may not exhibit substantial interval changes, regular follow-up with endoscopy may be necessary for cases with an initial size of 20 mm or larger, considering a possibility of malignancy.

Differentiating Gastrointestinal Stromal Tumors From Leiomyomas of Upper Digestive Tract Using Convolutional Neural Network Model by Endoscopic Ultrasonography

BACKGROUND

Gastrointestinal stromal tumors (GISTs) and leiomyomas are the most common submucosal tumors of the upper digestive tract, and the diagnosis of the tumors is essential for their treatment and prognosis. However, the ability of endoscopic ultrasonography (EUS) which could correctly identify the tumor types is limited and closely related to the knowledge, operational level, and experience of the endoscopists. Therefore, the convolutional neural network (CNN) is used to assist endoscopists in determining GISTs or leiomyomas with EUS.

MATERIALS AND METHODS

A model based on CNN was constructed according to GoogLeNet architecture to distinguish GISTs or leiomyomas. All EUS images collected from this study were randomly sampled and divided into training set (n=411) and testing set (n=103) in a ratio of 4:1. The CNN model was trained by EUS images from the training set, and the testing set was utilized to evaluate the performance of the CNN model. In addition, there were some comparisons between endoscopists and CNN models.

RESULTS

It was shown that the sensitivity and specificity in identifying leiomyoma were 95.92%, 94.44%, sensitivity and specificity in identifying GIST were 94.44%, 95.92%, and accuracy in total was 95.15% of the CNN model. It indicates that the diagnostic accuracy of the CNN model is equivalent to skilled endoscopists, or even higher than them.

CONCLUSION

While identifying GIST or leiomyoma, the performance of CNN model was robust, which is highlighting its promising role in supporting less-experienced endoscopists and reducing interobserver agreement.

Diagnostic yield of endoscopic and EUS-guided biopsy techniques in subepithelial lesions of the upper GI tract: a systematic review

BACKGROUND AND AIMS

Obtaining adequate tissue samples in subepithelial lesions (SELs) remains challenging. Several biopsy techniques are available, but a systematic review including all available techniques to obtain a histologic diagnosis of SEL is lacking. The aim of this study was to evaluate the diagnostic yield and adverse event rates of endoscopic biopsies, EUS-guided FNA (EUS-FNA), EUS-guided fine-needle biopsy (FNB) (EUS-FNB), and mucosal incision-assisted biopsy (MIAB) for SELs in the upper GI tract.

METHODS

A search strategy in multiple databases was performed. The primary outcome was diagnostic yield, defined as the percentage of procedures in which histology was obtained and resulted in a definitive histopathologic diagnosis. Secondary outcome measures included reported procedure-related adverse events, which were graded according to the AGREE (Adverse Events in Gastrointestinal Endoscopy) classification.

RESULTS

A total of 94 original articles were included. Studies were classified per endoscopic technique to obtain histopathology. This resulted in 8 included studies for endoscopic biopsy methods, 55 studies for EUS-FNA, 33 studies for EUS-FNB, and 26 studies for MIAB. Pooled rates for diagnostic yield were 40.6% (95% confidence interval [CI], 30.8-51.2) for endoscopic biopsy, 74.6% (95% CI, 69.9-78.7) for EUS-FNA, 84.2% (95% CI, 80.7-87.2) for EUS-FNB, and 88.2% (95% CI, 84.7-91.1) for MIAB. Reported procedure-related adverse events graded AGREE II or higher were 2.8% to 3.9% for endoscopic biopsies, 1.0% to 4.5% for EUS-FNA, .9% to 7.7% for EUS-FNB, and 1.9% to 7.9% for MIAB.

CONCLUSIONS

Based on the available evidence, MIAB and EUS-FNB seem to be most effective in terms of achieving a high diagnostic yield, with similar rates of adverse events.

Diagnostic Endoscopic Ultrasound (EUS) of the Luminal Gastrointestinal Tract

The purpose of this review is to focus on the diagnostic endoscopic ultrasound of the gastrointestinal tract. In the last decades, EUS has gained a central role in the staging of epithelial and sub-epithelial lesions of the gastrointestinal tract. With the evolution of imaging, the position of EUS in the diagnostic work-up and the staging flow-chart has continuously changed with two extreme positions: some gastroenterologists think that EUS is absolutely indispensable, and some think it is utterly useless. The truth is, as always, somewhere in between the two extremes. Analyzing the most up-to-date and strong evidence, we will try to give EUS the correct position in our daily practice.

Spectrum of endoscopic gastric subepithelial lesions encountered on EUS-FNA: A single center experience

BACKGROUND AND OBJECTIVES

Endoscopic ultrasound guided fine needle aspiration (EUS-FNA) is a minimally invasive and reliable non-surgical technique for the diagnosis of gastrointestinal lesions. The present study aimed to evaluate the spectrum of lesions encountered in the gastric subepithelium on EUS-FNA at a tertiary care center.

MATERIALS AND METHODS

Archival data of all patients undergoing EUS-FNA for gastric submucosal lesions over a period of 5 years was retrieved. Patient demographics, clinical presentation, and EUS findings were recorded along with the FNA results.

RESULTS

A total of 78 EUS-FNA samples were analyzed. Material was adequate in 62 cases (79.48%) and inadequate in 16 cases (12.82%) patients due to scant cellularity. Of the adequate samples, 34 (43.5%) were reported as neoplastic while 20 (25.64%) were non-neoplastic, and 8 (10.25%) were reported as suspicious of a neoplasm. In the neoplastic category, the predominant diagnosis was of spindle cell neoplasm comprising gastrointestinal stromal tumor (13), benign neural tumor (03), leiomyoma (02), and spindle cell tumors (03). The latter could not be categorized further due to a lack of IHC material. The next common diagnosis was adenocarcinoma (06) followed by neuroendocrine tumor (02) and poorly differentiated carcinoma (01). The non-neoplastic lesions included non-specific pathology (15), inflammatory lesions (08), and one case each of tuberculosis, pancreatic rest, and Brunner gland hamartoma. Cell blocks for ancillary testing were available in 54 cases (65.23%) and follow-up was available in 42 cases (53.84%).

CONCLUSION

EUS-FNA is a good modality for the diagnosis of gastric submucosal lesions with a high diagnostic yield.

Endoscopic Ultrasound in Cancer Staging

The authors review the role of endoscopic ultrasound (EUS) in the staging of cancers throughout the gastrointestinal tract. EUS offers an advantage over cross-sectional imaging in locoregional tumor staging but is less sensitive in identifying distant metastasis. The addition of FNA increases diagnostic accuracy and provides a tissue diagnosis. EUS combined with cross-sectional imaging is important in accurately staging GI tumors and thereby reducing unnecessary procedures and health care costs.

Tuberculosis of the Stomach Mimicking Gastric Submucosal Tumor: Diagnosis by Endoscopic Ultrasound

Introduction

Gastrointestinal tuberculosis (TB), specifically gastric TB, is a rare form of extrapulmonary TB. Diagnosis proves challenging with nonspecific signs and symptoms. In this case report, a 22-year-old male came in with complaints of recurrent hematemesis and melena.

Case Presentation

We found a submucosal mass with ulceration in the stomach cardia on esophagoduodenoscopy (EGD). The endoscopic ultrasound (EUS) finding was a hypoechoic submucosal lesion with a clear margin; specimens were taken using fine needle aspiration (FNA) for further histopathological examination. The result indicated granuloma of Mycobacterium Tuberculosis in pathology, suggesting that the diagnosis was gastric TB. The patient was then treated with antitubercular therapy regimen for 9 months. The previously documented mass in the stomach cardia was no longer visible on the follow-up endoscopy examination, and the patient was considered cured.

Conclusion

This case shows that gastric tuberculosis should be considered in patients with gastrointestinal symptoms, especially those living in TB endemic regions. Endoscopic examinations, such as EGD and EUS, may aid in the diagnosis of gastric tuberculosis.

Comparing endoscopic ultrasonography and double contrast-enhanced ultrasonography in the preoperative diagnosis of gastric stromal tumor

BACKGROUND

This study was designed to perform a comparative analysis between endoscopic ultrasonography (EUS) and double contrast-enhanced ultrasonography (DCEUS) for the preoperative diagnosis of gastric stromal tumors (GSTs).

METHODS

A retrospective study was conducted involving 139 patients with histologically confirmed GSTs. All patients preoperatively underwent DCEUS and EUS. The pathology reports were treated as the baseline and were retrospectively compared with the findings of EUS and DCEUS.

RESULTS

Of the 139 lesions, 120 and 113 were correctly identified by DCEUS and EUS, respectively, with an accuracy of 86.3% and 81.3%. The results revealed an insignificant difference between these two methods (p = 0.189).

CONCLUSIONS

DCEUS can display not only the locations, sizes, shapes, borders, internal echoes, but also show the blood perfusion patterns of GSTs. It is a highly accurate, noninvasive, and convenient method to be used at the pre-treatment stage.

Locally Advanced Glomus Tumor of the Stomach With Synchronous Liver Metastases: Case Report and Literature Review

Gastric glomus tumors (GGTs) are usually rare mesenchymal neoplasms. They are typically benign, with very few metastatic cases reported and no specific guidelines on their management. Here, we present a patient with a locally advanced GGT with synchronous liver metastases. One month after resection of the GGT, emergency laparotomy was required for massive hemoperitoneum due to bleeding from the largest metastasis. Indeed, a dramatic progression of liver metastases was observed in just one month. A wide local excision is considered the treatment of choice for GGTs. In particular, this case report suggests that the resection of any liver metastases should possibly be performed at the same time as the GGT excision and not at a later stage.

A Multimodal Multipath Artificial Intelligence System for Diagnosing Gastric Protruded Lesions on Endoscopy and Endoscopic Ultrasonography Images

INTRODUCTION

The aim of this study was to develop a novel artificial intelligence (AI) system that can automatically detect and classify protruded gastric lesions and help address the challenges of diagnostic accuracy and inter-reader variability encountered in routine diagnostic workflow.

METHODS

We analyzed data from 1,366 participants who underwent gastroscopy at Jiangsu Provincial People's Hospital and Yangzhou First People's Hospital between December 2010 and December 2020. These patients were diagnosed with submucosal tumors (SMTs) including gastric stromal tumors (GISTs), gastric leiomyomas (GILs), and gastric ectopic pancreas (GEP). We trained and validated a multimodal, multipath AI system (MMP-AI) using the data set. We assessed the diagnostic performance of the proposed AI system using the area under the receiver-operating characteristic curve (AUC) and compared its performance with that of endoscopists with more than 5 years of experience in endoscopic diagnosis.

RESULTS

In the ternary classification task among subtypes of SMTs using modality images, MMP-AI achieved the highest AUCs of 0.896, 0.890, and 0.999 for classifying GIST, GIL, and GEP, respectively. The performance of the model was verified using both external and internal longitudinal data sets. Compared with endoscopists, MMP-AI achieved higher recognition accuracy for SMTs.

DISCUSSION

We developed a system called MMP-AI to identify protruding benign gastric lesions. This system can be used not only for white-light endoscope image recognition but also for endoscopic ultrasonography image analysis.

Value of enhanced computed tomography in differentiating small mesenchymal tumours of the gastrointestinal from smooth muscle tumours

BACKGROUND

Computed tomography (CT) technology has been gradually used in the differentiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.

AIM

To explore the value of enhanced CT in the differentiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.

METHODS

Clinical data of patients with gastric mesenchymal or gastric smooth muscle tumours who were treated in our hospital from May 2018 to April 2023 were retrospectively analysed. Patients were divided into the gastric mesenchymal tumor group and the gastric smooth muscle tumor group respectively (n = 50 cases per group). Clinical data of 50 healthy volunteers who received physical examinations in our hospital during the same period were selected and included in the control group. Serum levels of carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), CA-125 and cytokeratin 19 fragment antigen 21-1 were compared among the three groups. The value of CEA and CA19-9 in the identification of gastric mesenchymal tumours was analysed using the receiver operating characteristic (ROC) curve. The Kappa statistic was used to analyse the consistency of the combined CEA and CA19-9 test in identifying gastric mesenchymal tumours.

RESULTS

CEA levels varied among the three groups in the following order: The gastric mesenchymal tumour group > the control group > the gastric smooth muscle tumour group. CA19-9 levels varied among the three groups in the following order: The gastric mesenchymal group > the gastric smooth muscle group > the control group, the difference was statistically significant (P < 0.05). ROC analysis showed that the area under the curve of CEA and CA19-9 was 0. 879 and 0. 782, respectively.

CONCLUSION

Enhanced CT has shown value in differentiating small mesenchymal tumors of the stomach and intestines from smooth muscle tumors.

A prospective randomized noninferiority trial comparing conventional smears and SurePathTM liquid-based cytology in endoscopic ultrasound-guided sampling of esophageal, gastric, and duodenal lesions

BACKGROUND

Several liquid-based cytology (LBC) methods are currently used, but the diagnostic accuracy of each method is not well known. We aimed to compare the diagnostic performance of SurePathTM LBC and conventional smear (CS) cytology in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) samples of esophageal, gastric, and duodenal lesions.

METHODS

As a prospective randomized noninferiority study, patients who needed EUS-FNA due to subepithelial mass in the upper gastrointestinal tract were randomly assigned 1:1 to the LBC and CS groups. Cytologic preparation was carried out using a crossover design where 1 method was used for the first needle-pass sample and another method was used for the second needle-pass sample. The primary outcome was to compare the diagnostic performance between LBC and CS using the final diagnosis as the gold standard.

RESULTS

A total of 87 patients were randomized and 60 patients were analyzed. There were no differences between LBC and CS in diagnostic accuracy (91.7% vs 86.7%, P = .380), sensitivity (97.7% vs 90.7%, P = .169), specificity (76.5% vs 76.5%, P > .99), negative predictive value (92.9% vs 76.5%, P = .225), or positive predictive value (91.3% vs 90.7%, P = .921). The background of LBC was less bloody than that of CSs (5.0% vs 53.3%, P < .001) and the sample preparation time of LBC was shorter than that of CSs (29 ± 7 seconds vs 90 ± 17 seconds, P < .001).

CONCLUSION

In the EUS-FNA of a subepithelial mass in the upper gastrointestinal tract, the diagnostic performance of LBC was not inferior to that of CS. The field of view was better in LBC, because the background was less bloody and necrotic. As LBC is more convenient to perform and takes shorter time, it is expected that it can replace the CS method for EUS-FNA samples.

EUS-Guided Diagnosis of Gastric Subepithelial Lesions, What Is New?

Gastric subepithelial lesions (SELs) are intramural lesions that arise underneath the gastric mucosa. SELs can be benign, but can also be malignant or have malignant potential. Therefore, correct diagnosis is crucial. Endosonography has been established as the diagnostic gold standard. Although the identification of some of these lesions can be carried out immediately, solely based on their echo characteristics, for certain lesions histological examination is necessary. Sometimes histology can be inconclusive, especially for smaller lesions. Therefore, new methods have been developed in recent years to assist decision making, such as contrast enhanced endosonography, EUS elastography, and artificial intelligence systems. In this narrative review we provide a complete overview of the gastric SELs and summarize the new data of the last ten years concerning the diagnostic advances of endosonography on this topic.

Reliability of endoscopic ultrasonography and endoscopy in measurement of gastric subepithelial tumor size

BACKGROUND

Subepithelial tumor (SET) size is important in determining the treatment plan; however, size estimation for gastric SETs has not been well investigated. We aimed to investigate which method predicts SET size most accurately by retrospectively analyzing surgically removed SETs.

METHODS

From January 2015 through June 2020, patients who underwent surgical gastric SET removal at Asan Medical Center, Seoul, Korea, were enrolled. SET sizes measured by pathologists and endoscopists were retrospectively reviewed. The reliability of SET size measurement by endoscopic ultrasonography (EUS) and endoscopy was calculated using intraclass correlation coefficient (ICC), with pathologic size as the gold standard.

RESULTS

Overall, EUS was highly reliable (ICC 0.86, P < 0.001), and endoscopy was moderately reliable (ICC 0.75, P < 0.001). When analyzed according to SET location, endoscopy was highly reliable in the lesser curvature's lower third (ICC 0.86, P = 0.014), middle third (ICC 0.88, P < 0.001), and upper third (ICC 0.90, P < 0.001); as well as the anterior wall's middle third (0.84, P < 0.001) and the posterior wall's upper third (ICC 0.80, P < 0.001). EUS (ICC 0.96, P = 0.005) and endoscopy (ICC 0.95, P = 0.008) both were most reliable for lower-third posterior wall lesions, whereas endoscopy was unreliable for middle-third greater curvature lesions (ICC 0.41, P = 0.05).

CONCLUSIONS

Both EUS and endoscopy were reliable methods for measuring gastric SET size, and overall, EUS was more reliable than endoscopy. In terms of SET location, EUS was consistently reliable, whereas endoscopy showed variable reliability. When measuring SET size by endoscopy, additional size measurements with EUS should be considered in certain locations.

AGA Clinical Practice Update on Management of Subepithelial Lesions Encountered During Routine Endoscopy: Expert Review

BEST PRACTICE ADVICE 1: Forceps bite-on-bite or deep-well biopsies or tunnel biopsies can sometimes establish a pathologic diagnosis of SEL. BEST PRACTICE ADVICE 2: EUS is the modality of choice to evaluate indeterminate SEL of the GI track and/or if non-diagnostic tissue by forceps biopsies. BEST PRACTICE ADVICE 3: SEL arising from the submucosa can be sampled using tunnel biopsies (or deep-well biopsies), EUS guided fine-needle aspiration (FNA), EUS guided fine-needle biopsy (FNB), or advanced endoscopic techniques (unroofing or endoscopic submucosal resection). BEST PRACTICE ADVICE 4: SEL arising from muscularis propria should be sampled (preferably using FNB or FNA) to determine whether the lesion is a GIST or leiomyoma. Structural assessment and staining will allow differentiation of mesenchymal tumors and assessing their malignant potential. BEST PRACTICE ADVICE 5: Endoscopic resection techniques have been described for removal of SEL and should be limited to endoscopists skilled in advanced tissue resection techniques. BEST PRACTICE ADVICE 6: Management of each SEL depends on the size of the lesion, histopathology, their malignant potential, and presence of symptoms. BEST PRACTICE ADVICE 7: SEL that have an endoscopic appearance consistent with a lipoma or pancreatic rest and normal mucosal biopsies do not need further evaluation or surveillance. BEST PRACTICE ADVICE 8: For SEL arising from muscularis propria that are less than 2 cm in size, surveillance using EUS should be considered. BEST PRACTICE ADVICE 9: Gastric GIST larger than 2 cm should be considered for resection. BEST PRACTICE ADVICE 10: Subepithelial lesions that are ulcerated, bleeding, or causing symptoms should be considered for resection.

Endoscopic submucosal dissection for proximal duodenal subepithelial lesions: a retrospective cohort study

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) has been used to remove subepithelial lesions (SELs) in recent years; however, duodenal ESD is associated with high rates of immediate or delayed bleeding and perforation. Whether ESD can be recommended for the treatment of duodenal SELs remains controversial. Therefore, we evaluated the efficacy and safety of ESD for duodenal SELs.

METHODS

We conducted a retrospective cohort study in 62 patients (62 lesions) who underwent ESD for duodenal SELs between January 2012 and December 2020. The therapeutic outcomes from ESD for duodenal SELs and procedure-related complications were analyzed.

RESULTS

En bloc resection and complete resection rates associated with duodenal ESD were 90.3% and 100%, respectively; four patients had a positive microscopic margin on pathologic examination. The median procedure time was 45 min (range 20-106 min). During the procedure, two patients received emergency surgery for uncontrolled bleeding and perforation, respectively. After the procedure, delayed bleeding occurred in three patients (4.8%), which was successfully managed by clipping, and delayed perforation occurred in two patients (3.2%) and needed emergency surgery. Risk factors related to complications were analyzed. Lesion size was found to be significantly associated with the complications (P = 0.028). No recurrences were detected, and no distant metastasis was observed in any patient during a median follow-up period of 45.5 months (range, 6-103 months).

CONCLUSION

Duodenal ESD is relatively safe and feasible for duodenal SELs, especially for lesions no more than 2 cm in size.

Application of artificial intelligence in the diagnosis of subepithelial lesions using endoscopic ultrasonography: a systematic review and meta-analysis

Endoscopic ultrasonography (EUS) is the most common method for diagnosing gastrointestinal subepithelial lesions (SELs); however, it usually requires histopathological confirmation using invasive methods. Artificial intelligence (AI) algorithms have made significant progress in medical imaging diagnosis. The purpose of our research was to explore the application of AI in the diagnosis of SELs using EUS and to evaluate the diagnostic performance of AI-assisted EUS. Three databases, PubMed, EMBASE, and the Cochrane Library, were comprehensively searched for relevant literature. RevMan 5.4.1 and Stata 17.0, were used to calculate and analyze the combined sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver-operating characteristic curve (SROC). Eight studies were selected from 380 potentially relevant studies for the meta-analysis of AI-aided EUS diagnosis of SELs. The combined sensitivity, specificity, and DOR of AI-aided EUS were 0.92 (95% CI, 0.85-0.96), 0.80 (95% CI, 0.70-0.87), and 46.27 (95% CI, 19.36-110.59), respectively). The area under the curve (AUC) was 0.92 (95% CI, 0.90-0.94). The AI model in differentiating GIST from leiomyoma had a pooled AUC of 0.95, sensitivity of 0.93, specificity of 0.88, PLR of 8.04, and NLR of 0.08. The combined sensitivity, specificity, and AUC of the AI-aided EUS diagnosis in the convolutional neural network (CNN) model were 0.93, 0.81, and 0.94, respectively. AI-aided EUS diagnosis using conventional brightness mode (B-mode) EUS images had a combined sensitivity of 0.92, specificity of 0.79, and AUC of 0.92. AI-aided EUS diagnosis based on patients had a combined sensitivity, specificity, and AUC of 0.95, 0.83, and 0.96, respectively. Additionally, AI-aided EUS was superior to EUS by experts in terms of sensitivity (0.93 vs. 0.71), specificity (0.81 vs. 0.69), and AUC (0.94 vs. 0.75). In conclusion, AI-assisted EUS is a promising and reliable method for distinguishing SELs, with excellent diagnostic performance. More multicenter cohort and prospective studies are expected to be conducted to further develop AI-assisted real-time diagnostic systems and validate the superiority of AI systems. Systematic Review Registration: PROSPERO (https://www.crd.york.ac.uk/PROSPERO/), identifier CRD42022303990.

Necessity of Individualized Approach for Gastric Subepithelial Tumor Considering Pathologic Discrepancy and Surgical Difficulty Depending on the Gastric Location

Background: Depending on the location of gastric subepithelial tumors (SETs), surgical access is difficult with a risk of postoperative complications. This study aimed to evaluate the clinicopathological characteristics of small-sized gastric SETs and their surgical outcomes depending on location and provide considering factors for their treatment plans. Methods: This single-center, retrospective study reviewed patients who underwent surgical resection for gastric SETs (size < 5 cm). SETs were divided into benign SETs and gastrointestinal stromal tumors (GISTs) for comparison. The clinicopathological characteristics of SETs in the cardia were compared to those in the other regions. Results: Overall, 191 patients with gastric SETs (135 GISTs, 70.7%; and 56 benign SETs, 29.3%) were included. In multivariate analysis, age > 65 years (odds ratio (OR), 3.183; 95% confidence interval (CI), 1.310−7.735; p = 0.011), and non-cardiac SETs (OR, 2.472; 95% CI, 1.110−5.507; p = 0.030) were associated with a significant risk of malignancy. Compared to SETs in other locations, cardiac SETs showed more complications (3 versus 0; p = 0.000), and open conversion rates (2 versus 0; p = 0.003). However, the proportion of GISTs of SETs in the cardia is not negligible (52.9%). Conclusions: Considering the malignancy risk of SETs, active surgical resection should be considered in old age and/or location in the non-cardiac area. However, in young patients, SETs located in the gastric cardia have a considerably benign nature and are associated with poor short-term surgical outcomes. An individualized surgical approach for asymptomatic small SETs according to the gastric location is warranted.

Gastrointestinal Stromal Tumors (GIST): A Population-Based Study Using the SEER Database, including Management and Recent Advances in Targeted Therapy

Introduction: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal (GI) system. Most GISTs originate from the interstitial cells of Cajal (ICC), the pacemaker cell situated between the circular and longitudinal layers of the muscularis propria along the GI tract. In this population-based study using the SEER database, we sought to identify demographic, clinical, and pathologic factors that affect the prognosis and survival of patients with this neoplasm. Molecular genetic advances, current management guidelines, and advances in targeted therapy are discussed. Methods: Demographic and clinical data from GIST patients were retrieved from the SEER research plus database for the period 2000−2018. Statistical analysis was performed with IBM SPSS® v20.2 software using the Chi-square test, paired t-test, multivariate analysis, and Kaplan−Meier functions. Results: A total of 10,833 patients with GIST were identified. Most patients were between 60−74 years of age: 40%, Caucasian: 68%, and the male to female ratio was 1.1:1. The most common primary tumor sites were stomach: 63%, small intestine: 30%, rectum: 3%, and esophagus: 0.7%. When reported, the grade of differentiation was well: 38%, moderately: 32%, undifferentiated: 19%, poorly: 12%. The size of most tumors ranged between 6−10 cm: 36% and they were treated by surgical intervention: 82% and/or chemotherapy/targeted therapy: 39%. The stage was localized: 66%, advanced: 19%, and regional: 15%. The 5-year survival was 74% (95% confidence interval (95% CI) = 72.6−74.7), and the 5-year cause-specific survival 82% (95% CI = 80.7−82.6). The 5-year cause-specific survival by treatment included surgery at 86% (95% CI = 85.4−87.3), chemotherapy/targeted therapy with or without surgery at 77% (95% CI = 75.7−78.9), and radiation at 75% (95% CI = 74.5−80). On multivariable analysis tumor size > 5 cm, poorly and undifferentiated grade, age > 60, and distant metastases at presentation were associated with worse overall survival. Conclusion: GISTs comprise 1−2% of malignancies of the GI tract, usually affect male Caucasians between the ages of 60 and 74 years, most tumors occur in the stomach and small intestine, and are usually >5 cm, but still localized, at the time of diagnosis. Most tumors receive multimodality surgical and chemotherapy/targeted therapy treatment, with a 5-year overall survival of 74% and cause-specific survival of 82%. GIST patients would benefit from enrollment in large clinical trials to establish better therapy guidelines for unresectable, treatment-refractory, and recurrent tumors.

Early gastric cancer presenting as a typical submucosal tumor cured by endoscopic submucosal dissection: A case report

BACKGROUND

Submucosal tumor (SMT)-like gastric cancer is rare, and almost all cases undergo curative surgical treatment because the submucosal layer is usually deeply invaded by tumor cells or because histopathologic types of SMT-like gastric cancer are undifferentiated or poorly differentiated. No report has been issued on an SMT-like gastric cancer cured by endoscopic resection alone or on changes in the endoscopic features of this type of tumor over several years.

CASE SUMMARY

We describe an exceptional case of a 53-year-old male with a 1.5 cm-sized SMT-like lesion covered by normal-appearing mucosa discovered by esophagogastroduodenoscopy (EGD) at the gastric antrum. Endoscopic ultrasound (EUS) visualized a homogeneous, well-circumscribed hypoechogenic lesion arising from the second sonographic layer with associated subtle obliteration of the third sonographic layer. Initial endoscopic biopsy was negative for neoplasm. The patient refused to undergo an invasive procedure and was subsequently lost to follow-up. Three years after initial detection, EGD revealed the lesion had become markedly erythematous, and at 4 years after initial EGD it had increased in size to 1.8 cm and developed a central ulcer and a heterogeneous EUS echo. Finally, endoscopic submucosal dissection (ESD) was performed, and histopathologic examination revealed a moderately differentiated adenocarcinoma had minutely invaded the submucosal layer (invasion depth 169 μm) but without lymphovascular invasion and with negative resection margins. Fortunately, no additional surgical treatment was required. He has been followed for 4 years after ESD without any evidence of local or distant recurrence.

CONCLUSION

This report describes an extremely rare case of early gastric cancer presenting as SMT that was cured by ESD after a treatment delay of 4 years and the endoscopic changes that occurred during this period. The report highlights the importance of considering the possibility of gastric cancer when SMT is encountered in clinical practice.

Natural History of Asymptomatic Esophageal Subepithelial Tumors of 30 mm or Less in Size

BACKGROUND

No definite guidelines for the management of small esophageal subepithelial tumors (SETs) have been established, because there are limited data and studies on their natural history. We aimed to assess the natural history and propose optimal management strategies for small esophageal SETs.

METHODS

Patients diagnosed as esophageal SETs ≤ 30 mm in size between 2003 and 2017 using endoscopic ultrasound (EUS) with a minimal follow-up of 3 months were enrolled, and their esophagogastroduodenoscopy (EGD) and EUS were retrospectively reviewed.

RESULTS

Of 275 esophageal SETs in 262 patients, the initial size was < 10 mm, 10-20 mm, and 20-30 mm in 104 (37.8%), 105 (38.2%), and 66 (24.0%) lesions, respectively. Only 22 (8.0%) SETs showed significant changes in size and/or echogenicity and/or morphology at a median of 40 months (range, 4-120 months). Tissues of 6 SETs showing interval changes were obtained using EUS-guided fine needle aspiration biopsy; 1 was identified as a gastrointestinal stromal tumor (GIST) and was surgically resected, while the other 5 were leiomyomas and were regularly observed. Eight SETs showing interval changes were resected surgically or endoscopically without pathological confirmation; 1 was a GIST, 2 were granular cell tumors, and the other 5 were leiomyomas.

CONCLUSION

Regular follow-up with EGD or EUS may be necessary for esophageal SETs ≤ 30 mm in size considering that small portion of them has a possibility of malignant potential. When esophageal SETs ≤ 30 mm show significant interval changes, pathological confirmation may precede treatment to avoid unnecessary resection.

Gastric submucosal lesion caused by an embedded fish bone: A case report

BACKGROUND

Submucosal tumors (SMTs) refer to elevated lesions that originate from the layers below the mucosa of the digestive tract, including the muscularis, submucosa and muscularis propria. With the development and application of endoscopy and endoscopic ultrasonography (EUS), the detection rate of SMTs has increased significantly in recent years. Various diseases can lead to SMTs. However, a foreign body embedded in the gastric antrum showing clinical manifestations of a SMT is rare.

CASE SUMMARY

We report the case of a 47-year-old woman, who presented with upper abdominal discomfort for one year, and was subsequently diagnosed with a gastric submucosal lesion caused by an embedded foreign body by EUS and computed tomography. Considering the size and potential complications of this lesion, endoscopic full-thickness resection was performed to achieve full resection in our endoscopy center. A fish bone was found in the lesion during the operation, and was successfully removed, and the defect was later closed with endoscopic purse-string sutures.

CONCLUSION

This case report highlights the management strategies of SMTs, the importance of being familiar with diagnostic methods related to submucosal lesions, and being able to conduct effective treatment when this rare condition is highly suspected.

Advancements in the Diagnosis of Gastric Subepithelial Tumors

A diagnosis of subepithelial tumors (SETs) is sometimes difficult due to the existence of overlying mucosa on the lesions, which hampers optical diagnosis by conventional endoscopy and tissue sampling with standard biopsy forceps. Imaging modalities, by using computed tomography and endoscopic ultrasonography (EUS) are mandatory to noninvasively collect the target's information and to opt candidates for further evaluation. Particularly, EUS is an indispensable diagnostic modality for assessing the lesions precisely and evaluating the possibility of malignancy. The diagnostic ability of EUS appears increased by the combined use of contrast-enhancement or elastography. Histology is the gold standard for obtaining the final diagnosis. Tissue sampling requires special techniques to break the mucosal barrier. Although EUS-guided fine-needle aspiration (EUS-FNA) is commonly applied, mucosal cutting biopsy and mucosal incision-assisted biopsy are comparable methods to definitively obtain tissues from the exposed surface of lesions and seem more useful than EUS-FNA for small SETs. Recent advancements in artificial intelligence (AI) have a potential to drastically change the diagnostic strategy for SETs. Development and establishment of noninvasive methods including AI-assisted diagnosis are expected to provide an alternative to invasive, histological diagnosis.

Canine Gastric Carcinomas: A Histopathological and Immunohistochemical Study and Similarities with the Human Counterpart

Simple Summary

Gastric carcinoma (GC) continues to be one of the leading causes of death in humans and is the most common neoplasm in the stomachs of dogs. In both species, previous studies have demonstrated that the disease is heterogeneous, with genetic and environmental factors playing a quintessential role in disease pathogenesis. Compared to humans, the incidence of gastric carcinoma in dogs is low although, in a small number of breeds, a higher incidence has been reported. In dogs, the etiology and molecular pathways involved remain largely unknown. This retrospective study reviews current signalment data, evaluates the inflammatory component and association with Helicobacter spp. presence in various canine gastric carcinoma histological subtypes, and investigates potential molecular pathways involved in one of the largest study cohorts to date. The benefit of such a comparative study is to highlight the parallel histological features and molecular pathways between dogs and humans.

Abstract

Canine gastric carcinoma (CGC) affects both sexes in relatively equal proportions, with a mean age of nine years, and the highest frequency in Staffordshire bull terriers. The most common histological subtype in 149 CGC cases was the undifferentiated carcinoma. CGCs were associated with increased chronic inflammation parameters and a greater chronic inflammatory score when Helicobacter spp. were present. Understanding the molecular pathways of gastric carcinoma is challenging. All markers showed variable expression for each subtype. Expression of the cell cycle regulator 14-3-3σ was positive in undifferentiated, tubular and papillary carcinomas. This demonstrates that 14-3-3σ could serve as an immunohistochemical marker in routine diagnosis and that mucinous, papillary and signet-ring cell (SRC) carcinomas follow a 14-3-3σ independent pathway. p16, another cell cycle regulator, showed increased expression in mucinous and SRC carcinomas. Expression of the adhesion molecules E-cadherin and CD44 appear context-dependent, with switching within tumor emboli potentially playing an important role in tumor cell survival, during invasion and metastasis. Within neoplastic emboli, acinar structures lacked expression of all markers, suggesting an independent molecular pathway that requires further investigation. These findings demonstrate similarities and differences between dogs and humans, albeit further clinicopathological data and molecular analysis are required.

A Review of Endoscopic Full-thickness Resection, Submucosal Tunneling Endoscopic Resection, and Endoscopic Submucosal Dissection for Resection of Subepithelial Lesions

Gastrointestinal subepithelial tumors (SETs) are often found while performing routine endoscopy. Recently, there has been the development of new endoscopic techniques such as endoscopic submucosal dissection, submucosal tunnel endoscopic resection, and endoscopic full-thickness resection, all minimally invasive approaches which have made it possible to resect SETs that were previously resected with surgery. This review discusses the endoscopic treatment of patients with SETs, outcomes for endoscopic treatment, procedure-related complications, and advantages and disadvantages of these endoscopic techniques.

Endoscopic diagnosis and management of gastric subepithelial lesions

PURPOSE OF REVIEW

The purpose of this manuscript is to provide an in-depth review of gastric subepithelial lesions (SELs) and describe the current approach to endoscopic diagnosis and management of these lesions.

RECENT FINDINGS

Gastric SELs are a relatively frequent finding on routine endoscopy (incidence 0.2-3%). A systematic approach to diagnosis and management is key because many SELs are of little consequence, while others carry a high risk of malignant transformation. Because esophagogastroduodenoscopy (EGD) cannot delineate depth of invasion or subepithelial appearance, endoscopic ultrasound (EUS) should be considered a first-line modality. Recent data suggest EUS-guided fine needle biopsy (FNB) may be superior to traditional fine needle aspiration (FNA) for the diagnosis of gastric SELs due to its ability to obtain histologic specimens for immunohistochemical staining. Alternative techniques for tissue sampling (combined with simultaneous resection) include submucosal resection, endoscopic submucosal dissection (ESD), submucosal tunnelling with endoscopic resection (STER) or endoscopic full-thickness resection (EFTR).

SUMMARY

This review details the endoscopic diagnosis and management of gastric SELs. Although EUS-guided sampling remains a first-line strategy (preferably with FNB), recent techniques including ESD, STER and EFTR have the potential to provide additional diagnostic and therapeutic options.

Submucosal Tunneling Endoscopic Resection

Minimally invasive endoscopic resection procedures continue to evolve, with submucosal tunneling endoscopic resection (STER) being a durable option for en bloc resection of submucosal tumors. Whether STER can be effectively used for larger (>3.5 cm) lesions remains to be seen. STER-ET is a novel approach for removal of extraluminal tumors, but data are currently limited to support its use.

Gastric Glomus Tumor

This case report describes glomus tumor of the stomach, a rare entity, which is a mesenchymal origin tumor. They are generally benign and account for nearly 1% of all gastrointestinal (GI) soft-tissue tumors. They are almost impossible to diagnose preoperatively because of the lack of specific characteristics and are often mistaken for GI stromal tumors (GISTs). In our hospital setup, a female aged 24 years, presented with right lumbar abdominal pain which after a thorough workup leads to the preoperative diagnosis of GIST, and distal gastrectomy with Roux-en-y anastomosis was done. However, pathological and immunohistochemical findings done after the surgery were found consistent with the diagnosis of gastric glomus tumor. Discovered on GIST-1 (DOG-1) nonreactivity is considered for the diagnosis of glomus tumor which helps in excluding the diagnosis of GIST, which is positive for DOG-1. Hence, it was concluded that differential diagnosis on the basis of immunohistochemical findings can lead to an accurate preoperative diagnosis and further targeted surgical intervention.

Reliability of Endoscopic Ultrasound Using Miniprobes and Grayscale Histogram Analysis in Diagnosing Upper Gastrointestinal Subepithelial Lesions

Background

To assess the role of endoscopic ultrasound (EUS) in the diagnosis of upper gastrointestinal subepithelial lesions (SELs) and to investigate EUS combined with a grayscale histogram analysis for the differentiation of leiomyomas and gastrointestinal stromal tumors (GISTs).

Methods

A retrospective study of 709 patients with upper gastrointestinal SELs was conducted by EUS before endoscopic resection. The EUS findings of SELs and pathological results after endoscopic resection were compared. The EUS images of SELs, particularly, leiomyoma and GIST, were further analyzed via a grayscale histogram to differentiate between the two tumors.

Results

Of the 709 patients, 47 cases were pathologically undetermined. The diagnostic consistency of EUS with endoscopic resection was 88.2% (584/662), including 185 muscularis mucosa, 61 submucosa, and 338 muscularis propria, respectively. The diagnostic consistency of EUS with pathology was 80.1% (530/662). The gray value of GISTs was significantly higher than that of leiomyomas (58.9 ± 8.3 vs. 39.5 ± 5.9, t = 57.0, P < 0.0001). The standard deviation of leiomyomas was significantly lower than that of GISTs (20.6 ± 7.0 vs. 39.8 ± 9.3, t = 23.7, P < 0.0001). The grayscale histogram analysis of GISTs showed higher echo ultrasound, and the echo of leiomyoma was more uniform.

Conclusion

EUS is the preferred procedure for the evaluation of upper gastrointestinal SELs. EUS combined with a grayscale histogram analysis is an effective method for the differentiation of leiomyomas and GISTs.

Clinical course of suspected small gastrointestinal stromal tumors in the stomach

BACKGROUND

Gastric subepithelial lesions are frequently encountered during endoscopic examinations, and the majority of them are small and asymptomatic. Among these lesions, gastrointestinal stromal tumors (GISTs) are the major concern for patients and clinicians owing to their malignant potentials. Although previous guidelines suggested periodic surveillance for such small (≤ 20 mm) lesions, several patients and clinicians have still requested or prescribed repeated examinations or radical resection, posing extra medical burdens and risks.

AIM

To describe the clinical course of suspected small gastric GISTs and provide further evidence for surveillance strategy for tumor therapy.

METHODS

This single-center, retrospective study was conducted at West China Hospital, Sichuan University. Consecutive patients with suspected small gastric GISTs were reviewed from November 2004 to November 2018. GIST was suspected according to endoscopic ultrasonography features: hypoechoic lesions from muscularis propria or muscularis mucosa. Eligible patients with suspected small (≤ 20 mm) GISTs were included for analysis. Patients’ demographic data, lesions’ characteristics, and follow-up medical records were collected.

RESULTS

A total of 383 patients (male/female, 121/262; mean age, 54 years) with 410 suspected small gastric GISTs (1 lesion in 362 patients, 2 lesions in 16, 3 lesions in 4, and 4 lesions in 1) were included for analysis. The most common location was gastric fundus (56.6%), followed by body (29.0%), cardia (12.2%), and antrum (2.2%). After a median follow-up of 28 mo (interquartile range, 16-48; range, 3-156), 402 lesions (98.0%) showed no changes in size, and size of 8 lesions (2.0%) was increased (mean increment, 10 mm). Of the 8 lesions with size increment, endoscopic or surgical resection was performed in 6 patients (5 GISTs and 1 leiomyoma). For other 2 remaining patients, unroofing biopsy or endoscopic ultrasound-guided fine-needle aspiration was carried out (2 GISTs), while no further change in size was noted over a period of 62-64 mo.

CONCLUSION

The majority of suspected small (≤ 20 mm) gastric GISTs had no size increment during follow-up. Regular endoscopic follow-up without pathological diagnosis may be highly helpful for such small gastric subepithelial lesions.