Background and Aim We aimed to develop a convolutional neural network (CNN)‐based object detection model for the discrimination of gastric subepithelial tumors, such as gastrointestinal stromal tumors (GISTs), and leiomyomas, in endoscopic ultrasound (EUS) images. Methods We used 376 images from 114 patients with histologically confirmed gastric GIST or leiomyoma to train the EUS‐CNN. We constructed the EUS‐CNN using an EfficientNet CNN model for feature extraction and a weighted bi‐directional feature pyramid network for object detection. We assessed the performance of our EUS‐CNN by calculating its accuracy, sensitivity, specificity, and area under receiver operating characteristic curve (AUC) using a validation set of 170 images from 54 patients. Four EUS experts and 15 EUS trainees were asked to judge the same validation dataset, and the diagnostic yields were compared between the EUS‐CNN and human assessments. Results In the per‐image analysis, the sensitivity, specificity, accuracy, and AUC of our EUS‐CNN were 95.6%, 82.1%, 91.2%, and 0.9234, respectively. In the per‐patient analysis, the sensitivity, specificity, accuracy, and AUC for our object detection model were 100.0%, 85.7%, 96.3%, and 0.9929, respectively. The EUS‐CNN outperformed human assessment in terms of accuracy, sensitivity, and negative predictive value. Conclusions We developed the EUS‐CNN system, which demonstrated high diagnostic ability for gastric GIST prediction. This EUS‐CNN system can be helpful not only for less‐experienced endoscopists but also for experienced ones. Additional EUS image accumulation and prospective studies are required alongside validation in a large multicenter trial.

Background and Aims: Colorectal polyps greater than 10 mm in size are often incompletely resected. Anchoring-endoscopic mucosal resection (A-EMR) is the technique of making a small incision at the oral side of the polyp using a snare tip after submucosal injection to avoid slippage during ensnaring. This study was performed to evaluate whether A-EMR could increase the complete resection rate for large colorectal polyps compared to conventional endoscopic mucosal resection (C-EMR). Methods: Polyps with sizes of 10–25 mm were randomly allocated to either the A-EMR group or the C-EMR group. Results: A total of 105 and 106 polyps were resected using A-EMR or C-EMR, respectively. In the intention-to-treat population, the complete resection rate was 89.5% in the A-EMR group and 74.5% in the C-EMR group (relative risk [RR], 1.20; 95% confidence interval [CI], 1.04–1.38; P=0.011). En bloc resection rate for the A-EMR and C-EMR group was 92.4% vs 76.4% (RR, 1.21; 95% CI, 1.06–1.37; P=0.005) and R0 resection rate was 77.1% vs 64.2% (RR, 1.18; 95% CI, 0.98–1.42; P=0.074), respectively. The total procedure time was 3.2 minutes (IQR, 2.6–4.1) in the A-EMR group and 3.0 minutes (IQR, 2.2–4.6) in the C-EMR group (median difference, 0.2; 95% CI, -0.22–0.73; P =0.250). There was a delayed bleeding and a perforation in C-EMR group, respectively. Conclusions: A-EMR was superior to C-EMR for the complete resection of large colorectal polyps. A-EMR can be considered one of the standard methods for the removal of colorectal polyps with sizes of 10 mm or greater.

Background/Aims: As the number of colonoscopies and polypectomies performed continues to increase in many Asian countries, there is a great demand for surveillance colonoscopy. The aim of this study was to investigate the adherence to postpolypectomy surveillance guidelines among physicians in Asia.Methods: A survey study was performed in seven Asian countries. An email invitation with a link to the survey was sent to participants who were asked to complete the questionnaire consisting of eight clinical scenarios.Results: Of the 137 doctors invited, 123 (89.8%) provided valid responses. Approximately 50% of the participants adhered to the guidelines regardless of the risk of adenoma, except in the case of tubulovillous adenoma ≥10 mm combined with high-grade dysplasia, in which 35% of the participants adhered to the guidelines. The participants were stratified according to the number of colonoscopies performed: ≥20 colonoscopies per month (high volume group) and <20 colonoscopies per month (low volume group). Higher adherence to the postpolypectomy surveillance guidelines was evident in the high volume group (60%) than in the low volume group (25%). The reasons for nonadherence included concern of missed polyps (59%), the low cost of colonoscopy (26%), concern of incomplete resection (25%), and concern of medical liability (15%). Conclusions:A discrepancy between clinical practice and surveillance guidelines among physicians in Asia was found. Physicians in the low volume group frequently did not adhere to the guidelines, suggesting a need for continuing education and appropriate control. Concerns regarding the quality of colonoscopy and complete polypectomy were the main reasons for nonadherence.

Purulent pericarditis is a rare condition with a high mortality rate. We report a case of purulent pericarditis subsequently caused by Candida parapsilosis, Peptostreptococcus asaccharolyticus, Streptococcus anginosus, Staphylococcus aureus, Prevotella oralis, and Mycobacterium tuberculosis in a previously healthy 17-year-old boy with mediastinal tuberculous lymphadenitis. The probable route of infection was a bronchomediastinal lymph node-pericardial fistula. The patient improved with antibiotic, antifungal, and antituberculous medication in addition to pericardiectomy.

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Background and Aim The complete and safe removal of large (≥ 20 mm) colorectal lesions is an area of concern. Endoscopic submucosal dissection (ESD) effectively removes these lesions compared with endoscopic mucosal resection (EMR). However, ESD requires advanced techniques, longer procedure time, and high cost. Precutting EMR (EMR‐P) is a modified EMR method that overcomes the limitations of EMR. This study aimed to compare the efficacy and safety of EMR‐P and ESD in large (20–30 mm) flat colorectal lesions. Methods This was a retrospective analysis of cases in which 20‐ to 30‐mm flat colorectal lesions were resected at Seoul St. Mary's Hospital from January 2014 to December 2019. Propensity score matching was performed to control for possible confounders. Results Two hundred and ninety‐nine patients were included in this study. After matching, 90 patients were assigned to each group. There were no significant difference in complete resection rates (92.2% vs 92.2%, P = 1.000), en bloc resection rates (95.6% vs 97.8%, P = 0.682), and mean size of lesions (22.9 ± 3.1 mm vs 23.0 ± 3.1 mm, P = 0.867) between EMR‐P and ESD. Procedure time was significantly shorter with EMR‐P (11.0 ± 6.5 min vs 37.0 ± 19.3 min, P < 0.001). The adverse events rate was not significantly different between both groups. No local recurrence occurred in both groups. Conclusions Precutting EMR was not significantly different to ESD in terms of complete resection rate and en bloc resection rate for 20‐ to 30‐mm flat colorectal lesions without fibrosis. Furthermore, EMR‐P has shorter procedure time than ESD. EMR‐P could be considered one of standard treatments for large flat colorectal lesions.

Desmoid tumors are rare soft tissue tumors considered to have locally infiltrative features without distant metastasis until now. Although they are most commonly intraabdominal, very few cases have extra-abdominal locations. The origin of intrathoracic desmoid tumors is predominantly the chest wall with occasional involvement of pleura. True intrathoracic primary desmoid tumors with no involvement of the chest wall or pleura are extremely rare. We recently experienced a case of true intrathoracic desmoid tumor presenting as multiple lung nodules at 13 years after resection of a previous intraabdominal desmoid tumor.

Background: Patients with end-stage renal disease (ESRD) have a higher incidence of clinically relevant complications, such as bleeding and perforation after polyp resection, compared to patients without underlying diseases. Cold snare polypectomy (CSP) is increasingly used for the removal of small polyps and diminutive polyps due to its shorter procedure time and low risk of bleeding and perforation. However, there have been few studies on the effectiveness and safety of CSP in patients with ESRD. The aim of this study was to compare the efficacy and safety of CSP and endoscopic mucosal resection (EMR) in ESRD patients. Methods: This study was a retrospective study. We performed propensity score-matched analysis in patients with ESRD who underwent endoscopic resection for 3–10-mm-sized colorectal polyps at Seoul St. Mary's Hospital, from January 2014 to December 2019. Results: After 1:1 ratio matching, 406 polyps were included: 203 polyps were resected with CSP and 203 polyps with EMR. There was no difference between the CSP group and EMR group in incomplete resection rate (4.43% vs. 1.97%, P = 0.16). There were no differences between the CSP and EMR group for immediate bleeding (5.42% vs. 7.88%, P = 0.32) and delayed bleeding (0% vs. 0.49%, P = 1.00). No perforation occurred in either group. Conclusions: There were no differences between the CSP and EMR group in terms of efficacy and safety. CSP can be one of the standard methods for the removal of 3–10-mm-sized colorectal polyps in patients with ESRD.