Prevalence, natural progression, and clinical practices of upper gastrointestinal subepithelial lesions in Korea: a multicenter study

Diagnostic accuracy and influencing factors of microprobe endoscopic ultrasound for gastrointestinal subepithelial lesions: a multicenter retrospective study

BACKGROUND

Microprobe endoscopic ultrasonography (MEUS) has been widely adopted in primary hospitals due to its affordability, ease of use, and simple operation. This study aims to assess the diagnostic accuracy of MEUS in classifying gastrointestinal subepithelial lesions (SELs), identify key influencing factors, and explore strategies for improvement.

METHODS

A retrospective analysis was conducted on 855 patients with histopathologically confirmed SELs across five Chinese hospitals. The overall diagnostic accuracy (DA) of MEUS for SELs was calculated. Independent factors were identified using univariate and multivariate logistic regression analyses, followed by subgroup analysis.

RESULTS

Among 896 lesions across 31 SEL types, the overall DA was 70.31%. Non-gastrointestinal stromal tumor (GIST) and non-neuroendocrine tumor (NET) lesions, along with gastric location, were identified as risk factors for lower diagnostic accuracy, while rectal location was protective. In the subgroup analysis, gastric leiomyomas had a DA of 9.85% with 99.17% incorrectly classified as GISTs, compared to 94.78% for gastric GISTs, 84.24% for gastric NETs, and 31.2% for other lesions. Lesions with inhomogeneous echoes were 20 times more likely than those with homogeneous echoes to be diagnosed as gastric GISTs compared to gastric leiomyoma. Additionally, the inhomogeneous echo patterns of gastric GISTs were characterized by hyperechogenic spots in 93.67%, marginal halos in 18.99%, and cystic changes in 13.92%.

CONCLUSION

MEUS is effective for classifying SELs, although differentiating between gastric GISTs and leiomyomas remains challenging. Improved assessment of echo heterogeneity and expanded knowledge of atypical and rare cases may enhance diagnostic accuracy.

Advancements in Endoscopic Treatment for Gastric Subepithelial Tumors

Peroral flexible endoscopy is a minimally invasive technique that enables the local resection of gastric subepithelial tumors (SETs) with malignant potential. Resection techniques are mainly chosen on the basis of the lesion size. Minute SETs less than 1 cm should be managed through a watch and wait strategy, with the exception of histologically diagnosed superficial lesions, which require endoscopic mucosal resection or endoscopic submucosal dissection. For 1- to 3-cm small SETs, endoscopic enucleation techniques, such as endoscopic submucosal excavation, submucosal tunneling endoscopic resection, and peroral endoscopic tumor resection, can be used. However, endoscopic full-thickness resection is preferred for histologically complete removal with negative surgical margins. When endoscopic full-thickness resection is considered technically difficult, laparoscopic and endoscopic cooperative surgery (LECS) is a safe and dependable alternative. Moderate-sized SETs (3 to 5 cm) require surgical intervention because the lesions must be removed transabdominally. LECS is a less invasive surgical procedure as it reduces the resection area; however, some LECS techniques that require transoral tumor retrieval are not available. Endoscopic intervention for lesions larger than 5 cm should be used with caution for research purposes. With advancements in endoscopic diagnosis, the indications for endoscopic treatment for SETs are expected to improve, thereby enhancing patients' quality of life.

The efficacy and safety of submucosal tunneling endoscopic resection in treating large esophageal subepithelial lesions

BACKGROUND

Submucosal tunneling endoscopic resection (STER) is considered an effective, safe and minimally invasive treatment for esophageal subepithelial lesions (SELs) with maximal dilameter less than 3.0 cm, yet its efficacy for lesions over 3.0 cm remains unclear. This study aimed to evaluate the application value of STER for SELs of varying sizes.

METHODS

Consecutive patients with esophageal SELs who underwent STER were retrospectively enrolled from May 2017 to March 2024. Baseline characteristics, surgical information and prognosis were collected and compared among patients with SELs of different sizes, as defined by the maximal diameter of the postoperative specimen.

RESULTS

A total of 133 patients were included, among whom 69 with SELs < 3.0 cm, 31 with SELs between 3.0 and 5.0 cm, 33 with SELs ≥ 5.0 cm. 1 case with SELs ≥ 5.0 cm was converted to endoscopic submucosal dissection (ESD) due to the tumor's adhesion to the epithelial layer. Among those who completed the STER procedure, the en bloc resection rate was 100.0% for all three subgroups, and the recurrence and metastasis rates were 0.0%, demonstrating that STER is effective for SELs of all sizes. However, SELs ≥ 5.0 cm were associated with more adverse events, a higher number of difficult procedures, and more frequent intensive care unit (ICU) transfers (all p < 0.050).

CONCLUSIONS

STER is effective and safe for treating esophageal SELs. For lesions exceeding 5 cm, while still feasible, the procedure requires meticulous planning, advanced techniques and careful monitoring due to increased complexity and risks.

Natural Course and Long-Term Outcomes of Gastric Subepithelial Lesions: A Systematic Review

Background/Objectives: Gastric subepithelial lesions (SELs) are often incidentally detected during endoscopic examinations, with most patients being asymptomatic and lesions measuring <20 mm. Despite their generally indolent nature, certain SELs, such as gastrointestinal stromal tumors, require resection. Current guidelines recommend periodic surveillance; however, the natural course and long-term outcomes of gastric SELs have not been sufficiently investigated. This systematic review aimed to synthesize evidence on the progression, growth rate, and risk factors associated with gastric SELs to inform clinical management strategies. Methods: A comprehensive search of PubMed was conducted for peer-reviewed studies published between January 2000 and November 2024. Eligible studies included original studies on the follow-up and progression of gastric SELs. Non-English articles, reviews, case reports, and unrelated topics were excluded. In total, 277 articles were screened, with 15 additional articles identified through manual screening. Ultimately, 41 articles were included in the analysis. The study protocol is registered in PROSPERO (CRD42024614865). Results: Large-scale studies reported low growth rates of 2.0-8.5% over 2.0-5.0 years, while smaller studies reported a broader range of growth rates of 5.4-28.4%. The factors contributing to these discrepancies include patient selection, follow-up duration, and growth criteria. Risk factors for lesion size increase include larger initial lesion size, irregular margins, heterogeneous echo patterns, and certain tumor locations. Conclusions: These findings underscore the need for individualized management strategies based on lesion size, imaging characteristics, and risk factors. The close monitoring of high-risk lesions is crucial for timely intervention. Standardized growth criteria and optimized follow-up protocols are essential for improving clinical decision making and patient outcomes.

Artificial Intelligence-Based Diagnosis of Gastric Mesenchymal Tumors Using Digital Endosonography Image Analysis

Background/Objectives: Artificial intelligence (AI)-assisted endoscopic ultrasonography (EUS) diagnostic tools have shown excellent performance in diagnosing gastric mesenchymal tumors. This study aimed to assess whether incorporating clinical and endoscopic factors into AI-assisted EUS classification models based on digital image analysis could improve the diagnostic performance of AI-assisted EUS diagnostic tools. Methods: We retrospectively analyzed the data of 464 patients who underwent both EUS and surgical resection of gastric mesenchymal tumors, including 294 gastrointestinal stromal tumors (GISTs), 52 leiomyomas, and 41 schwannomas. AI-assisted classification models for GISTs and non-GIST tumors were developed utilizing clinical and endoscopic factors and digital EUS image analysis. Results: Regarding the baseline EUS classification models, the area under the receiver operating characteristic (AUC) values of the logistic regression, decision tree, random forest, K-nearest neighbor (KNN), and support vector machine (SVM) models were 0.805, 0.673, 0.781, 0.740, and 0.791, respectively. Using the new classification models incorporating clinical and endoscopic factors into the baseline classification models, the AUC values of the logistic regression, decision tree, random forest, KNN, and SVM models increased to 0.853, 0.715, 0.896, 0.825, and 0.794, respectively. In particular, the random forest and KNN models exhibited significant improvement in performance in Delong's test (both p < 0.001). Conclusion: The diagnostic performance of the AI-assisted EUS classification models improved when clinical and endoscopic factors were incorporated. Our results provided direction for developing new AI-assisted EUS models for gastric mesenchymal tumors.

A Case of Esophageal MALT Lymphoma Mimicking a Subepithelial Tumor

Mucosa-associated lymphoid tissue (MALT) lymphoma, also known as extranodal marginal zone lymphoma, is a low-grade B-cell lymphoma that can develop in the mucosal layer of various organs, including the gastrointestinal tract, salivary glands, lungs, and skin. The most common site is the gastrointestinal tract, particularly the stomach. On the other hand, primary esophageal lymphomas are extremely rare. MALT lymphomas can undergo histological transformation into more aggressive B-cell lymphomas, such as diffuse large B-cell lymphoma, resulting in a poor prognosis. This paper reports a rare case of primary esophageal MALT lymphoma mimicking a subepithelial tumor located in the lower esophagus that was treated successfully with radiotherapy. MALT lymphoma should be included in a differential diagnosis when subepithelial tumors are found in the esophagus, particularly if endoscopic ultrasonography reveals the tumor to be located in the deep mucosal and submucosal layers. Following the precise diagnosis, accurate staging and appropriate treatment are crucial. Regular follow-up is necessary to assess the possibility of recurrence or transformation to high-grade lymphoma.

A 65-Year-Old Man Presenting to the Emergency Department with Gastric Hemorrhage Caused by a Glomus Tumor

BACKGROUND Glomus tumor is a benign but rapidly growing mesenchymal tumor that is a rare in the gastrointestinal tract, can be locally invasive due to its rapid growth, and can result in perforation of a viscus. We report a 65-year-old man presenting as an emergency with gastric hemorrhage and gastric glomus tumor. CASE REPORT A 65-year-old man came to our hospital for a life-threatening upper digestive hemorrhage. The preoperative examinations (digestive endoscopy without sampling of biopsy fragments and contrast-enhanced computer tomography) led to the presumptive diagnosis of gastrointestinal stromal tumor. Wedge resection of the gastric wall was performed. The histopathological examinations revealed a proliferation of round-oval cells of medium size with a solid disposition and in nests. This proliferation dissected the muscular tunic and caused ulceration of the gastric mucosa. Immunohistochemical tests confirmed the diagnosis of glomus tumor and excluded other diagnoses (neuroendocrine tumor or gastrointestinal stromal tumor). The postoperative evolution was favorable, and at the time of discharge, the biochemical test values normalized. CONCLUSIONS Pathologists are faced with a challenging task due to the deceptive appearance that can be presented by such a rare tumor. Histopathological and immunohistochemical examinations are essential in achieving a precise diagnosis and assessing the biological potential of the glomus tumor. Even if it is a benign tumor, the clinical picture it causes can still be a major risk to the patient's life. Consequently, ensuring effective case management becomes crucial, as it requires a thorough comprehension of all conditions encompassed in the differential diagnosis.