Background Current guidelines suggest that routine biopsy of post-endoscopic mucosal resection (EMR) scars can be abandoned, provided that a standardized imaging protocol with virtual chromoendoscopy is used. However, few studies have examined the accuracy of advanced endoscopic imaging, such as narrow-band imaging (NBI) vs. white-light endoscopy (WLE) for prediction of histological recurrence. We aimed to assess whether NBI accuracy is superior to that of WLE and whether one or both techniques can replace biopsies. Methods The study was a multicenter, randomized, pathologist-blind, crossover trial, with consecutive patients undergoing first colonoscopy after EMR of lesions ≥ 20 mm. Computer-generated randomization and opaque envelope concealed allocation. Patients were randomly assigned to scar examination with NBI followed by WLE (NBI + WLE), or WLE followed by NBI (WLE + NBI). Histology was the reference method, with biopsies being performed for all tissues. Results The study included 203 scars (103 in the NBI + WLE group, 100 in the WLE + NBI group). Recurrence was confirmed histologically in 29.6 % of the scars. The diagnostic accuracy of NBI was not statistically different from that of WLE (95 % [95 %CI 92 %–98 %] vs. 94 % [95 %CI 90 %–97 %]; P = 0.48). The negative predictive values (NPVs) were 96 % (95 %CI 93 %–99 %) for NBI and 93 % (95 %CI 89 %–97 %) for WLE (P = 0.06). Conclusions The accuracy of NBI for the diagnosis of recurrence was not superior to that of WLE. Endoscopic assessment of EMR scars with WLE and NBI achieved an NPV that would allow routine biopsy to be avoided in cases of negative optical diagnosis.

O conceito de Prevenção Quaternária, um questionamento sobre a base da ação médica, nasceu na articulação da relação médico-paciente. Refere-se a toda a atividade médica, sendo uma importante ferramenta para a medicina de família. É uma interrogação ética sobre os excessos da demasiada e demasiadamente pouca medicina e fornece algumas respostas.

58-year-old female, with a medical history of stage IIB Hodgkin lymphoma in remission for over 5 years post-chemoradiation, and treated invasive breast and renal carcinomas, was incidentally diagnosed with a cardiac gastric polyp on a follow-up computed tomography (CT). Upper endoscopy and endoscopic ultrasound (EUS) revealed a 50mm ulcerated polypoid subepithelial lesion (Figure 1) originating from a small stalk in the muscularis propria (MP). Biopsies and fine needle biopsy were inconclusive but without epithelial neoplastic tissue. Subsequent staging showed no lymph nodes or distant metastasis. Given the high morbidity associated with surgery – total gastrectomy –, the tumor's small insertion in the MP, the patient's lack of lymph node involvement or distant metastasis, and their preference for a less invasive approach, endoscopic submucosal dissection (ESD) was chosen as the optimal treatment option. En bloc ESD was performed without technical difficulties, revealing the lesion’s superficial origin in the MP (Fig. 2), which eliminated the need for perforation and subsequent defect closure. However, because of its dimension and shape, the specimen was fragmented during retrieval. Histological analysis confirmed gastric leiomyosarcoma with non-evaluable margins (Figure 3). Following multidisciplinary discussion, surveillance was recommended. At 12-months follow-up, the patient remains with no signs of recurrence at CT and endoscopic evaluation. Primary leiomyosarcoma of the stomach is an extremely rare neoplasm[1], that can arise from the muscularis propria (more frequently) or the muscularis mucosa, with the latter presenting as intraluminal type and the former as infiltrative[2]. Ionizing radiation and Epstein-Barr virus have been suggested as associated risk factors[2]. Imaging diagnosis is often achieved using CT scans and EUS, which are valuable tools in evaluating these cases, specially the latter one as it enables the sampling of deeper tumor tissues with ultrasound-guided fine-needle aspiration. However, as demonstrated in our case, distinguishing leiomyosarcomas from other gastric tumors with these methods can be challenging. Endoscopic biopsies are also frequently ineffective due to the submucosal origin of the lesion. Smooth muscle tumors, including leiomyoma and leiomyosarcoma, typically show positivity for smooth muscle markers such as actin, desmin, and h-caldesmon, while they are generally negative for c-kit (CD-117) and CD-34[3]. Surgical resection remains the standard treatment for smooth muscle tumors, as it allows for complete removal of the neoplasm and provides the best chance for curative outcomes[4]. However, there are limited reports in the literature exploring the use of ESD to treat these tumors[5]. ESD offers the advantage of en bloc resection, which is particularly beneficial for managing localized disease. In this case, although the specimen fragmented during retrieval—a potential disadvantage of this technique—the lesion itself was resected en bloc during the ESD, which is the most critical factor for achieving optimal clinical outcomes. While fragmentation may limit certain aspects of histological examination, the complete en bloc resection during ESD remains the primary determinant of clinical success. This approach can potentially minimize morbidity and mortality associated with more invasive surgical procedures, making ESD a viable alternative in selected cases in which the tumor is confined and surgical risks are high.

Background and Study Aims: Positron emission tomography/computed tomography (PET/CT) with 2-[18F]FDG (FDG) has been increasingly used to detect or monitor neoplasms. Gastrointestinal tract (GIT) is one of the most common sites of FDG uptake, leading to increasing requests for endoscopic examinations. We aimed to evaluate the nature and significance of unexpected PET/CT-FDG findings in the GIT. Patients and Methods: We retrospectively analyzed 371 consecutive patients with incidental GIT findings on PET/CT-FDG between June 2016 and October 2021 who were subsequently referred to endoscopic examinations. Demographic data, PET/CT-FDG results, endoscopic findings, and histological analysis were analyzed. Results: Of 194 colonic incidental uptakes, 102 (52.6%) corresponded to at least premalignant lesions, being 57 (29.4%) advanced adenomas and 23 (11.9%) adenocarcinomas. Of 193 upper GIT incidental uptakes, there were 11 (13.8%) esophageal and 14 (14.4%) gastric malignant/premalignant lesions. The maximum standardized uptake value (SUVmax) significantly varied according to the nature of the lesion, being higher in malignant lesions (in the esophagus, stomach, and colon). However, an optimal SUVmax cutoff was only found for stomach (SUVmax 8.2; sensitivity of 79% and specificity of 76%). There was a significant association between the site of uptake and the nature of the lesion – left colon and gastric body uptake were associated with neoplastic origin whereas rectum and lower esophagus were associated with inflammatory or no endoscopic changes. Conclusions: Any incidental uptake in the lower GIT should be investigated provided that patients are suitable for further treatment. However, in the upper GIT the characteristics of uptake on 18F‐FDG‐PET/CT may allow to select those who need endoscopic examination.

Introduction and Aims: Underwater endoscopic mucosal resection (U-EMR) emerged as a promising alternative to conventional EMR (C-EMR) for resecting large colorectal polyps. There is a lack of studies focusing on its learning curve. Thus, we aimed to determine the learning curve of U-EMR in endoscopists without prior experience in U-EMR. Methods: Four endoscopists from 4 different centres performed U-EMR after standardized online training. Patients with nonpedunculated colorectal lesions sized 10-30mm were enrolled between November 2023 and June 2024. The primary outcome was to evaluate technical success, en bloc resection rates, procedural time, and adverse events before and after 10 and 15 procedures, to assess whether this threshold is sufficient for proficiency. Results: Overall, 84 lesions were included, median size of 17mm [10-35mm]. Mean procedural time was 3.99 minutes, with an average of 1.21 piecemeal fragments per lesion, and en bloc resection rate was 85%, with all lesions completely resected. When comparing learning phases, en bloc resection rates were 83.3% in the first period (first 15 lesions) and 87.5% thereafter, with a slight reduction in mean procedural time (4.13 vs 3.77 minutes). There were no significant differences in procedural time or en bloc resection when comparing results after 10 or 15 procedures, no observed improvements after the 16th. No perforations, delayed bleeding, or hospital admissions. Intraprocedural bleeding occurred in 3.6% of cases, managed conservatively. Prophylactic clip closure was performed in 34.5% of cases, primarily in right colon. Conclusion: U-EMR is safe, efficient, and easily adopted, with proficiency that may be achieved after a small number of procedures.