B-cell lymphomas, particularly diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), are the most common intestinal lymphomas. The histological type can be distinguished based on the site and endoscopic findings. DLBCL is often found in the ileocecum and is frequently classified as ulcerative or polypoid. Considering the risk of perforation during chemotherapy, surgical treatment can be considered in patients with intestinal DLBCL. FL is usually detected endoscopically as multiple white nodules in the second portion of the duodenum, and the watch-and-wait approach is mostly adequate because of the indolent clinical course of the condition. Mucosa-associated lymphoid tissue (MALT) lymphoma often involves the rectum, and its treatment is diverse, including endoscopic resection. Immunoproliferative small-intestinal disease (IPSID) is a subtype of gastrointestinal MALT lymphoma. Mantle cell lymphoma (MCL) is typically found as multiple lymphomatous polyposis and is classified as a low-grade B-cell lymphoma, including FL and MALT lymphoma. It is important to distinguish MCL from both FL and MALT lymphomas because the aggressive clinical course of the former necessitates different management strategies. Intestinal T-cell lymphomas have been partially renamed in the latest WHO 5th edition. If there is a case of iatrogenic immunodeficiency, the possibility of an Epstein-Barr virus-positive mucocutaneous ulcer needs to be considered as a diagnosis, and the condition is characterized by spontaneous remission after immunosuppression reduction or discontinuation.

EUS-BD is an alternative technique for patients with failed endoscopic retrograde cholangiopancreatography. EUS-BD is usually indicated for patients with distal biliary obstruction. Recently, EUS-BD has also been applied to hilar biliary obstruction. Despite advancements in various devices and techniques, EUS-BD for hilar biliary obstruction remains challenging owing to the need for an endoscopic approach to the right hepatic lobe. In this report, we describe technical tips for EUS-BD for hilar biliary obstruction and review the relevant literature.

The association between Helicobacter pylori （H. pylori） infection and gastric mucosa-associated lymphoid tissue （MALT） lymphoma and gastric carcinoma is well known. However, the occurrence of both these diseases is rare. Here, we report a case of a collision tumor comprising MALT lymphoma and early gastric cancer in a stomach uninfected by H. pylori. A 71-year-old man diagnosed with gastric cancer on physical examination was referred to our hospital. Upper gastrointestinal endoscopy showed a 15 mm area of faded mucosa with an adjacent 7 mm area of reddened mucosa in the greater curvature of the upper gastric body. Biopsy indicated that the former was a MALT lymphoma and the latter was a moderately differentiated adenocarcinoma. Since gastric mucosal atrophy was not observed, H. pylori antibody in the serum was less than 3 U/mL, H. pylori microscopic examination of the resected specimen was negative, and there was no history of eradication, the patient was identified as H. pylori- uninfected. EUS revealed that the cancer had invaded deep into the submucosal layer. Chest and abdominal CT revealed no lymph node enlargement. Tumor marker and soluble IL-2 receptor levels were within normal range. A segmental gastrectomy with lymph node dissection was performed. Histological examination of the resected specimens showed contact between the MALT lymphoma and the early gastric cancer. Both lesions were successfully treated and neither local recurrence nor metastasis was observed.

An 87-year-old woman presented to our hospital for a routine gastrostomy exchange. During the exchange procedure, the guidewire was removed, and we unsuccessfully attempted to insert a new bumper-button catheter from outside the body using an extraction device without the guidewire. Thereafter, a local injection needle was inserted through the forceps hole of the endoscope into the gastric side of the fistula. Next, the tip of the local injection needle was guided out of the body and a guidewire was fixed to its tip using plastic tape. The local injection needle was pulled into the stomach using a guidewire, which then successfully secured access to the fistula. A new catheter was inserted percutaneously with the extraction device along the guidewire. This case demonstrates that, if percutaneous insertion is difficult during gastrostomy exchange, it may be possible to reinsert the device endoscopically from the gastric side.

The 64-year-old male patient with pancreatitis associated with ulcerative colitis (UC) had previously been treated with steroids, tacrolimus, or infliximab. He developed toxic megacolon and subsequently underwent a subtotal colectomy and ileostomy. Approximately five months postoperatively, the patient presented with anorexia. An EGD revealed small yellow spots and erosions in the stomach with deep duodenal ulcers that extended from the duodenal bulb to the horizontal portion. Therefore, the patient was diagnosed with UC-related gastroduodenal lesions and was administered crushed mesalazine, following which the ulcer improved. However, a duodenal stricture was observed, prompting the patient to undergo endoscopic balloon dilation of the strictures. Subsequently, the patientʼs clinical course was uneventful. Notably, there are no previous reports on the efficacy of endoscopic balloon dilatation for UC-related upper gastrointestinal lesions with stenosis.

A 50-year-old woman with a 2-year history of bronchial asthma presented with abdominal pain and diarrhea, followed by purpura and painful hypesthesia in the lower extremities and limb weakness. Laboratory data showed markedly increased eosinophils in peripheral blood. Eosinophilic gastroenteritis was suspected; therefore, a CS was performed that revealed multiple irregular erosions, shallow ulcers, and redness of the surrounding mucosa throughout the terminal ileum and colon. During CS, a polyp containing mild inflammatory changes in the sigmoid colon was identified and removed via EMR. Pathological findings included numerous eosinophilic infiltrations and granulomatous vasculitis. Based on the clinical findings, eosinophilic granulomatosis with polyangiitis was diagnosed according to the criteria of the Ministry of Health, Labor and Welfare. The diagnosis was confirmed by histological evaluation of the submucosa in the EMR specimen, which also contained a coexisting colorectal adenoma.

A systematic instructional approach is crucial for beginners to develop foundational technical skills in esophagogastroduodenoscopy. The operation of an endoscope involves three types of movements: forward and backward movements, angling, and rotational movements. To effectively control devices such as biopsy forceps with the right hand, proper manipulation of the endoscope with the left hand is essential. Therefore, mastering the rotational movements of the endoscope using the left forearm and wrist, as well as performing angling operations with the left hand alone, is critical. Additionally, it is important to maintain a “C-shaped curve” in the endoscope, avoiding any bends, to ensure that torque is efficiently transmitted to the tip of the endoscope. This report outlines the fundamental technical skills necessary for performing esophagogastroduodenoscopy.

To start ERCP, EUS, EUS-FNA/therapeutic EUS, trainees should first learn the indications, procedures, EUS anatomy, complications, and treatment. Second, training at a high-volume center is recommended. Observation of the instructorʼs performance and assistance with these procedures should be the primary step. Third, the trainees should start the procedures with the permission of the instructor after gaining sufficient understanding of how to perform them. Fourth, although individual variations exist, at least one or more training period with 200-300 ERCPs, 250-600 EUSs, and 40-80 EUS-FNA/FNBs are necessary to achieve competency. Fifth, compliance with more difficult ERCPs and therapeutic EUS requires several years of training in a high-volume center.

Objectives: We aimed to evaluate the efficacy of texture and color enhancement imaging (TXI), which allows the acquisition of brighter images with enhanced color and surface structure in colorectal polyp detection compared to white light imaging.

Methods: Patients who underwent colonoscopy with repeated ascending colon observation using TXI and white light imaging between August 2020 and January 2021 were identified in three institutions. The outcomes included the mean number of adenomas detected per procedure (MAP), adenoma detection rate (ADR), and ascending colonic adenoma miss rate (Ac-AMR). Logistic regression was used to determine the effects of the variables on the outcomes.

Results: We included 1043 lesions from 470 patients in the analysis. The MAP, ADR, flat polyp detection rate, and Ac-AMR in TXI and white light imaging were 1.5% (95% confidence interval 1.3-1.6%) vs. 1.0% (0.9-1.1%), 58.2% (51.7-64.6%) vs. 46.8% (40.2-53.4%), 66.2% (59.8-72.2%) vs. 49.8% (43.2-56.4%), and 17.9% (12.1-25.2%) vs. 28.2% (20.0-37.6%), respectively. TXI, age, withdrawal time, and endoscopy type were identified as significant factors affecting the MAP and the ADR using multivariate regression analysis.

Conclusions: Our study indicates that TXI improve the detection of colorectal neoplastic lesions. However, prospective randomized trials are required to confirm these findings.