There are few reports on the usefulness of endoscopic ultrasound-guided tissue acquisition (EUS-TA) for upper gastrointestinal subepithelial lesions (SELs) < 20 mm with on-site stereomicroscopic assessment.

This study is aimed at investigating the usefulness of EUS-TA combined with on-site stereomicroscopic assessment using fine-needle biopsy (FNB) for SELs < 20 mm.

Participants (n = 133) underwent EUS-TA combined with on-site stereomicroscopic assessment using a 22-gauge FNB needle for upper gastrointestinal SELs between January 2018 and January 2022. We conducted a comparative study of diagnostic results after dividing the participants into two groups on the basis of lesion size: < 20 and ≥ 20 mm.

There were 42 cases in the < 20-mm group and 91 cases in the ≥ 20-mm group. The diagnostic yield of EUS-TA in all cases was 97.7%, with values of 97.6% in the < 20-mm group and 97.8% in the ≥ 20-mm group and no significant difference between the groups. A total of 298 passes were made. The tissue sampling rate was 99.0%, and specimens with stereomicroscopically visible white cores (SVWCs) ≥ 4 mm were sampled at a rate of 87.2%. There was no significant difference in the sampling rate of specimens with SVWCs ≥ 4 mm between the groups. The diagnostic sensitivity in specimens with SVWC ≥ 4 mm was 98.5% (256/260 passes). Multivariate analysis showed that this factor significantly contributed to diagnosis (odds ratio 24.396, 95% confidence interval: 1.6596-4.7292, p < 0.001).

EUS-TA using a FNB needle combined with on-site stereomicroscopic assessment is a useful diagnostic method for < 20-mm SELs.

Previous research has conducted meta-analyses on the diagnostic accuracy of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB). However, studies on adverse events (AEs) have been limited and sporadic and have included a highly diverse group of patients (with upper and lower gastrointestinal tract issues) and needles of varying sizes (19-22-25G). The purpose of this systematic review and meta-analysis was to determine the incidence of AEs related to the utilization of 20-22G second-generation EUS-FNB needles subsequent to puncture of the upper gastrointestinal tract and adjacent organs.

We searched the PubMed, Embase, and SCIE databases from January 1, 2010, to December 31, 2023. The primary outcome was percentage of summary AEs. Subgroup analyses were based on needle type, needle size, and lesion site.

A total of 99 studies were included in the analysis, with 9303 patients. The overall AE rate for 20-22G second generation EUS-FNB needles in upper gastrointestinal EUS-FNB was 1.8% (166/9303), with bleeding being the most common AE at 44.0%. The percentages of pancreatitis, abdominal pain, and other AEs were 24.1%, 21.1%, and 10.8%, respectively. Patients undergoing hepatic EUS-FNB had the highest incidence of AEs at 14.0%, followed by submucosal lesions at 3.2% and pancreatic lesions at 2.6%.

EUS-FNB is a safe procedure with a relatively low risk of upper gastrointestinal AEs (1.8%) and no associated deaths. Postoperative bleeding and pancreatitis are the most common complications of EUS-FNB. Most AEs are mild and self-limiting in severity, and serious complications are very rare.

Gastrointestinal schwannomas (GIS) are rare neurogenic tumors arising from Schwann cells in the gastrointestinal tract. Studies on GIS are limited to small case reports or focus on specific tumor sites, underscoring the diagnostic and therapeutic challenges they pose.

To comprehensively examine the clinical features, pathological characteristics, treatment outcomes, associated comorbidities, and prognosis of GIS.

The study population included patients diagnosed with GIS at the First Affiliated Hospital, Zhejiang University School of Medicine, between June 2007 and April 2024. Data were retrospectively collected and analyzed from medical records, including demographic characteristics, endoscopic and imaging findings, treatment modalities, pathological evaluations, and follow-up information.

In total, 229 patients with GIS were included, with a mean age of 56.00 years and a male-to-female ratio of 1:1.83. The mean tumor size was 2.75 cm, and most (76.9%) were located in the stomach. Additionally, 6.6% of the patients had other malignant tumors. Preoperative imaging and endoscopy frequently misdiagnosed GIS as gastrointestinal stromal tumors. However, accurate preoperative diagnosis was achieved using endoscopic ultrasound-guided fine-needle aspiration combined with immunohistochemical analysis, in which S100 and SOX-10 markers were mostly positive. Smaller tumors were typically managed with endoscopic resection, while larger lesions were treated with surgical resection. Follow-up results showed that most patients experienced favorable outcomes.

Preoperative diagnosis of GIS via clinical characteristics, endoscopy, and imaging examinations remains challenging but crucial. Endoscopic therapy provides a minimally invasive and effective option for patients.

The concept of macroscopic on-site evaluation (MOSE) was introduced in 2015 when the endoscopist observed better diagnostic yield when the macroscopically visible core on MOSE was superior to 4 mm. Recent studies suggest that MOSE by the endoscopist may be an excellent alternative to rapid on-site evaluation, and some classifications have been published. Few studies have assessed the adequacy of histologic cores in MOSE during endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/FNB).

To evaluate the performance of MOSE during EUS-FNA/FNB.

This multicentric prospective study was conducted in 16 centers in 3 countries (Egypt, Iraq, and Morocco) and included 1108 patients with pancreatic, biliary, or gastrointestinal pathology who were referred for EUS examination. We prospectively analyzed the MOSE in 1008 patients with available histopathological reports according to 2 classifications to determine the adequacy of the histological core samples. Data management and analysis were performed using a Statistical Package for Social Sciences (SPSS) version 27.

A total of 1074 solid lesions were biopsied in 1008 patients with available cytopathological reports. Mean age was 59 years, and 509 patients (50.5%) were male. The mean lesion size was 38 mm. The most frequently utilized needles were FNB-Franseen (74.5%) and 22 G (93.4%), with a median of 2 passes. According to 2 classifications, 618 non-bloody cores (61.3%) and 964 good samples (95.6%) were adequate for histological evaluation. The overall diagnostic yield of cytopathology was 95.5%. The cytological examination confirmed the diagnosis of malignancy in 861 patients (85.4%), while 45 samples (4.5%) were inconclusive. Post-procedural adverse events occurred in 33 patients (3.3%). Statistical analysis showed a difference between needle types (P = 0.035) with a high sensitivity of FNB (97%). The analysis of the relationship between the MOSE-score and the final diagnosis showed a significant difference between the different scores of the MOSE (P < 0.001).

MOSE is a simple method that allows endoscopists to increase needle passes to improve sample quality. There is significantly higher FNB sensitivity and cytopathology diagnostic yield with good MOSE cores.

Recently, artificial intelligence (AI) has been applied to clinical diagnosis. Although AI has already been developed for gastrointestinal (GI) tract endoscopy, few studies have applied AI to endoscopic ultrasound (EUS) images. In this study, we used a computer-assisted diagnosis (CAD) system with deep learning analysis of EUS images (EUS-CAD) and assessed its ability to differentiate GI stromal tumors (GISTs) from other mesenchymal tumors and their risk classification performance.

A total of 101 pathologically confirmed cases of subepithelial lesions (SELs) arising from the muscularis propria layer, including 69 GISTs, 17 leiomyomas and 15 schwannomas, were examined. A total of 3283 EUS images were used for training and five-fold-cross-validation, and 827 images were independently tested for diagnosing GISTs. For the risk classification of 69 GISTs, including very-low-, low-, intermediate- and high-risk GISTs, 2,784 EUS images were used for training and three-fold-cross-validation.

For the differential diagnostic performance of GIST among all SELs, the accuracy, sensitivity, specificity and area under the receiver operating characteristic (ROC) curve were 80.4%, 82.9%, 75.3% and 0.865, respectively, whereas those for intermediate- and high-risk GISTs were 71.8%, 70.2%, 72.0% and 0.771, respectively.

The EUS-CAD system showed a good diagnostic yield in differentiating GISTs from other mesenchymal tumors and successfully demonstrated the GIST risk classification feasibility. This system can determine whether treatment is necessary based on EUS imaging alone without the need for additional invasive examinations.

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.

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.

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.

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.

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the first-choice procedure for obtaining pathological tissue samples from gastrointestinal (GI) subepithelial lesions (SELs). However, its diagnostic accuracy is lower than that for pancreatic masses owing to puncture difficulty and the need for immunostaining for definitive diagnosis. The advent of fine-needle biopsy needles, which have become well known in recent years, improves the diagnostic accuracy of EUS-FNA for GI SELs. The forward-viewing echoendoscope and rapid on-site evaluation (ROSE) have also helped to improve diagnostic accuracy. Furthermore, in facilities where ROSE is not available, endosonographers perform a macroscopic on-site evaluation. With these procedural innovations, EUS-FNA is now performed aggressively even for SELs smaller than 20 mm. The incidence of procedure-related adverse events such as bleeding and infection is low, and thus, EUS-FNA can be safely performed to diagnose SELs.

In stereomicroscopic sample isolation processing, the cutoff value (≥4 mm) of stereomicroscopically visible white cores indicates high diagnostic sensitivity. We aimed to evaluate endoscopic ultrasound-guided tissue acquisition (EUS-TA) using a simplified stereomicroscopic on-site evaluation of upper gastrointestinal subepithelial lesions (SELs).

In this multicenter prospective trial, we performed EUS-TA using a 22-gauge Franseen needle in 34 participants with SELs derived from the upper gastrointestinal muscularis propria, requiring pathological diagnosis. The presence of stereomicroscopically visible white core (SVWC) in each specimen was assessed using stereomicroscopic on-site evaluation. The primary outcome was EUS-TA's diagnostic sensitivity with stereomicroscopic on-site evaluation based on the SVWC cutoff value (≥4 mm) for malignant upper gastrointestinal SELs.

The total number of punctures was 68; 61 specimens (89.7%) contained stereomicroscopically visible white cores ≥4 mm in size. The final diagnoses were gastrointestinal stromal tumor, leiomyoma, and schwannoma in 76.5%, 14.7%, and 8.8% of the cases, respectively. The sensitivity of EUS-TA with stereomicroscopic on-site evaluation based on the SVWC cutoff value for malignant SELs was 100%. The per-lesion accuracy of histological diagnosis reached the highest level (100%) at the second puncture.

Stereomicroscopic on-site evaluation showed high diagnostic sensitivity and could be a new method for diagnosing upper gastrointestinal SELs using EUS-TA.

The present study aimed to evaluate the clinical value of macroscopic on-site evaluation (MOSE) of solid masses by endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) using a standard 22-gauge needle and to explore the cut-off length of macroscopic visible core (MVC) required to obtain an accurate histopathological diagnosis. In total, 119 patients who satisfied the inclusion and exclusion criteria and underwent EUS-FNA were divided into conventional FNA and FNA combined with MOSE groups. In the MOSE group, the presence of MVC was examined and its total length measured, after which the pathological results of FNA were compared with the final diagnosis. The diagnostic sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of FNA in the two groups were calculated and the effect of MOSE on the FNA result was analyzed. The MOSE group had a higher diagnostic sensitivity (75.0% vs. 89.8%; P=0.038) and accuracy (74.5% vs. 90.6%; P=0.026). MVC was observed in 98.4% (63/64) of patients in the MOSE group. The median length of MVC was 15 mm. The optimal cut-off length of MVC for obtaining an accurate histological diagnosis was 13 mm, with a sensitivity of 90.2%. No statistically significant significance was observed in the specificity, PPV and NPV between the groups. Thus, MOSE helps to improve the diagnostic ability of FNA for solid masses and may be a useful alternative to assess the adequacy of puncture specimens in units where rapid on-site evaluation cannot be performed.

Subepithelial lesions, formerly known as subepithelial tumors, are incidentally discovered protrusions throughout the gastrointestinal tract with normal overlying mucosa. Studies related to the diagnosis and therapy methods are limited due to the low incidence and malignant potential of these lesions. They commonly originating from the second, third, and fourth layers (muscularis mucosa, submucosa, and muscularis propria) of the gastrointestinal wall. They are reported to be more prevalent in the stomach and esophagus than small intestine and colon. Subepithelial lesions in the stomach and duodenum are more prone to malignancy than the lesions in the esophagus. Despite different strategies in the management of subepithelial lesions based on their size and location, there is still not a unique consensus on the issue. In this review, we have attempted to introduce the most practical approach to managing gastrointestinal subepithelial lesions based on current guidelines.

Up till now, there are still controversies about the specific indication of endoscopic resection for small gastric subepithelial tumors (gSETs) originating from muscularis propria. We aimed to investigate the safety of endoscopic resection and postoperative pathology analysis.

The patients with primary small gSETs originating from muscularis propria, treated by endoscopic resection in the endoscopic center of Shengjing Hospital between January, 2011 and September, 2019 were enrolled. The complete resection rate, adverse events and clinicopathological features were recorded.

A total of 936 patients with 972 gastric SETs ≤ 2 cm originating from muscularis propria were included in our study. All the lesions were successfully treated by endoscopic resection. Nearly half of lesions were proved to be gastrointestinal stromal tumor (GIST) [n = 411 (42.3%)] according to postoperative pathology. All the objects were further subdivided into 2 groups, ≤ 1 cm, > 1 and ≤ 2 cm gSETs. The risk of gastric GIST of intermediate/high risk in the group (> 1 and ≤ 2 cm gSETs) is 8.41 times as that of gastric GIST in the group (the size of gastric ≤ 1 cm gSETs) (P < 0.05).

Endoscopic resection is a safe and effective treatment for small gSETs. gSETs (1-2 cm) is more risky than gSETs (≤ 1 cm) and should be resected. This should be evaluated by further studies.

We aimed to develop a new artificial intelligence (AI)-based method for evaluating endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) specimens in pancreatic diseases using deep learning and contrastive learning. We analysed a total of 173 specimens from 96 patients who underwent EUS-FNB with a 22 G Franseen needle for pancreatic diseases. In the initial study, the deep learning method based on stereomicroscopic images of 98 EUS-FNB specimens from 63 patients showed an accuracy of 71.8% for predicting the histological diagnosis, which was lower than that of macroscopic on-site evaluation (MOSE) performed by EUS experts (81.6%). Then, we used image analysis software to mark the core tissues in the photomicrographs of EUS-FNB specimens after haematoxylin and eosin staining and verified whether the diagnostic performance could be improved by applying contrastive learning for the features of the stereomicroscopic images and stained images. The sensitivity, specificity, and accuracy of MOSE were 88.97%, 53.5%, and 83.24%, respectively, while those of the AI-based diagnostic method using contrastive learning were 90.34%, 53.5%, and 84.39%, respectively. The AI-based evaluation method using contrastive learning was comparable to MOSE performed by EUS experts and can be a novel objective evaluation method for EUS-FNB.

We reviewed a total of 60 consecutive patients who underwent both S-MOSE and rapid on-site cytopathological evaluation (ROSE) during EUS-FNB between July 2019 and October 2020, and the usefulness of S-MOSE in comparison with histology was evaluated. A 22-gauge Franseen needle was used to perform EUS-FNB in all patients, and only the specimens obtained by the first pass were evaluated. The final diagnosis was based on the surgical specimen or the clinical course consistent with the EUS-FNB results.

The final diagnoses of the 60 patients included 45 patients with pancreatic ductal adenocarcinoma, 6 with autoimmune pancreatitis, 4 with mass-forming pancreatitis, 1 with pancreatic metastasis, 2 with pancreatic neuroendocrine tumor, and 2 with intraductal papillary mucinous carcinoma. The histological diagnostic accuracy of the first pass of EUS-FNB was 83.3% (50/60). The agreement between the S-MOSE and the histological diagnosis was 90% (54/60). The positive predictive value of S-MOSE for histological diagnosis was 90.7%, which can be an indicator of when to stop the EUS-FNB procedure. There were no immediate or delayed adverse events reported after the FNB based on the chart and medical visit history review.

In the EUS-FNB of SPLs, S-MOSE can be an alternative to ROSE for specimen evaluation and has the potential to shorten the procedure time.

We herein report the first case of metastatic pancreatic leiomyosarcoma derived from the urinary bladder diagnosed by an endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) in a 65-year-old woman. The patient had undergone total cystectomy for bladder leiomyosarcoma. Four years thereafter, a nodule was observed in her left lung on chest computed tomography. Suspecting primary lung cancer, pulmonologists at our hospital recommended a thoracoscopic lung biopsy, which the patient refused. Five years post-cystectomy, fluorodeoxyglucose positron emission tomography revealed enlargement of the left lung nodule and a new mass in the pancreatic head. She was referred to our department for the pathological diagnosis of a pancreatic head mass by an EUS-FNB. The EUS-FNB yielded adequate pancreatic tissue for an immunohistochemical analysis. A diagnosis of metastatic pancreatic lesion originating from the urinary bladder was made. In atypical pancreatic tumors, the utilization of an EUS-FNB and immunohistochemical analysis can help establish an accurate diagnosis.

A schwannoma is a tumor originating from Schwann cells. It is occasionally observed in the abdominal viscera in the form of a submucosal tumor derived from the gastric or duodenal muscularis propria. To date, only a few studies have reported on pancreatic schwannomas. Furthermore, very few patients are preoperatively diagnosed with pancreatic schwannoma because of the lack of established imaging characteristics distinguishing this type of schwannoma from other conditions. We herein report the first English publication of pancreatic schwannoma in which surgery was avoided because a pathological diagnosis was made solely on the basis of endoscopic ultrasound-guided fine-needle aspiration findings.