Duodenal adenomas and carcinomas are clinically and histologically divided into ampullary and non-ampullary tumors. Non-ampullary tumors are classified into intestinal or stomach type based on the mucin phenotype. The intestinal type can occur anywhere in the duodenum, but the gastric type is more common in the proximal duodenum (oral side of papilla of Vater), suggesting a high degree of malignancy. Due to the higher rate and severity of complications, endoscopic resection for superficial non-ampullary duodenal tumors was not actively performed in Japan for a long time. However, the development of a new treatment method enables us to perform endoscopic resection more safely. On the other hand, some cases of adenoma were observed without resection. From the cases with long follow-up periods, the carcinogenesis rate was not so high. The treatment strategy should be decided taking into consideration potential complications, risk of carcinogenesis, the patientʼs condition, and prognosis. With appropriate evaluation of lesions based on understanding the characteristics and natural history of duodenal adenomas and adenocarcinomas, proper treatment strategies should be selected.

Endoscopic ultrasonography (EUS) plays a particularly important role in the diagnosis of pancreatic disease. In recent years, with the development and improvements of the EUS scope and ultrasonic diagnostic equipment, EUS has been used for detection and making a qualitative diagnosis of pancreatic diseases. With the advent of color Doppler, power Doppler, ultrasound contrast agents, and ultrasound imaging method, the diagnostic approach for pancreatic disease, which is difficult to diagnose, has entered a new stage. In this paper, the role and usefulness of contrast-enhanced endoscopic ultrasonography (CE-EUS) for pancreatic disease, including the development and improvements of EUS equipment, are reviewed.

CE-EUS is indicated for the differential diagnosis of solid pancreatic tumors and cystic lesions of the pancreas, especially for diagnosis of the nodules or mucous masses in neoplastic cysts, and diagnosis of the stage of malignant pancreatic tumors (i.e., evaluation of mainly vascular invasion). In the EUS diagnosis of pancreatic disease, qualitative diagnosis becomes possible by adding blood flow information using an ultrasound contrast agent (CE-EUS), and the diagnostic accuracy has improved (not only sensitivity but also specificity has increased). Reports on the usefulness of CE-EUS have accumulated. Two meta-analyses of differential diagnosis of pancreatic solid masses, especially pancreatic cancer, by CE-EUS reported a sensitivity of 93-94% and a specificity of 88-89%, and its usefulness is described in the 2019 Pancreatic Cancer Practice Guidelines. CE-EUS diagnosis of cystic pancreatic lesions, especially neoplastic cysts, was reported to have a sensitivity of 100% and a specificity of 80-97% for identifying mural nodules. It is also reported that analysis of malignant nodule size, nodule / pancreatic parenchymal contrast ratio analysis, and analysis of mural nodule morphology and vascular distribution pattern are useful for the differential diagnosis between malignant or benign intraductal papillary mucosal neoplasms (IPMNs). From these reports, it is expected that a more accurate diagnosis of pancreatic diseases can be made faster than ever by CE-EUS.

Aim: This study aimed to investigate the relationship between the pattern of gastric lanthanum deposition and gastric mucosal atrophy.

Methods: We retrospectively reviewed 4 patients with gastric lanthanum deposition who tested negative for Helicobacter pylori infection (non-atrophy group) and 10 patients with gastric lanthanum deposition with gastric atrophy (atrophy group). The endoscopic features of gastric lanthanum deposition were retrospectively analyzed in both groups.

Results: Although gastric lanthanum deposition appears as white lesions, this presentation was not observed in 1 of the 4 patients in the non-atrophy group. The remaining 3 patients (75%) had diffuse white lesions in the gastric body that were predominantly distributed in the posterior wall and lesser curvature. In the atrophy group, white lesions were found in 9 of the 10 cases. In the areas with atrophic mucosa, white lesions were most frequently found in the gastric antrum (n = 5) and angle (n = 5). The white lesions appeared in an annular and/or granular pattern. White lesions were also found in the gastric body with mucosal atrophy and presented in an annular pattern (n = 1) or as diffuse whitish lesions (n = 1). Based on these findings, we speculate that in patients without gastric mucosal atrophy, gastric lanthanum deposition appears as diffuse white lesions in the posterior wall and lesser curvature of the gastric body. In the gastric mucosa with atrophy, lanthanum-related lesions likely appear as annular or granular white lesions. Moreover, these white lesions are probably more frequently observed in the gastric antrum and angle since atrophy begins at the lower part of the stomach.

Conclusions: These findings suggest that the localization and macroscopic findings of gastric lanthanum deposition differ depending on the presence or absence of gastric atrophy.

A 73-year-old woman had a submucosal tumor of 5 mm in diameter at the gastric cardia. On the basis of findings from esophagogastroduodenoscopy and endoscopic ultrasonography, the lesion was thought to be a neuroendocrine tumor. However, pathological examination of the biopsy specimen could not provide a definitive diagnosis. We treated the lesion with endoscopic mucosal resection with ligation device (EMR-L). The final diagnosis was lymphoepithelial cyst. This is the first case of gastric lymphoepithelial cyst treated by endoscopic resection. Gastric lymphoepithelial cyst is very rare and further accumulation of cases is necessary.

A 70-year-old man with chronic renal failure who was undergoing hemodialysis was referred to our hospital for epigastralgia. Computed tomography (CT) revealed a common bile duct stone. Endoscopic sphincterotomy (EST) was performed to remove the stone. Four days after EST, he developed shock with melena. CT revealed an aneurysm in the papilla of Vater. Angiography demonstrated rupture of aneurysm of the posterior superior pancreaticoduodenal (PSPD) artery. Selective transcatheter arterial embolization (TAE) with intravascular microcoils was performed and hemostasis was achieved. Aneurysm of the PSPD artery following EST is very rare, and TAE is one of the effective therapeutic maneuvers for post-EST hemorrhage.

A 74-year-old woman presented to our hospital with constipation. Colonoscopic examination revealed laterally spreading tumors (LSTs) in the ascending colon and transverse colon. Endoscopic mucosal resection (EMR) was performed. Two days later, she complained of stomachache and fever. Laboratory examination showed increased levels of inflammatory markers. Abdominal computed tomography and endoscopic ultrasonography revealed that the mucosa of the transverse colon was edematous. Intussusception was thought to have formed. We treated this intussusception by surgery. The EMR clip and hematoma seemed to have caused intussusception.

We report this case of colonic intussusception that occurred after EMR and was treated with surgical therapy.

We report a rare case of right-sided colitis showing cobblestone-like appearance and multiple shallow ulcers associated with familial Mediterranean fever. A 60-year-old man presented with a recent history of several episodes of high fever, abdominal pain and diarrhea. Gene analysis showed variations of the MEFV gene in the exon 3 and exon 8 splicing donor sites. Oral administration of colchicine was effective for relief of his signs and symptoms and improvement of colitis as demonstrated by colonoscopy. He had two gastric ulcer scars in the gastric antrum with gastric fundic polyps, and the healed colonic mucosa was covered with intestinal spirochetes.

Endoscopic necrosectomy is performed for patients with walled off necrosis (WON) that does not respond to endoscopic ultrasound (EUS)-guided drainage. However, endoscopic necrosectomy is associated with high rates of adverse events and it is a highly invasive procedure. The addition of transmural naso-cyst continuous irrigation (TNCCI) to EUS-guided drainage can help to avoid endoscopic necrosectomy. TNCCI is performed by inserting an external tube and an internal tube from the gastroduodenal lumen into the WON under EUS guidance and then the WON is continuously irrigated with saline. In cases in which this procedure is ineffective, internal tubes are inserted into the WON under endoscopic guidance and then TNCCI is performed. In TNCCI, necrotic material can be removed by continuously irrigating the WON without performing endoscopic necrosectomy. EUS-guided drainage with TNCCI is an effective and safe approach to treat WON. We recommend that this method is performed before considering endoscopic necrosectomy.

Background and Aim: An antireflux metal stent (ARMS) for nonresectable distal malignant biliary obstruction (MBO) may prevent recurrent biliary obstruction (RBO) as a result of duodenobiliary reflux and prolong time to RBO (TRBO). Superiority of ARMS over conventional covered self-expandable metal stents (SEMS) has not been fully examined.

Methods: We conducted a multicenter randomized controlled trial to examine whether TRBO of an ARMS with a funnel-shaped valve was longer than that of a covered SEMS in SEMS-naïve patients. We enrolled 104 patients (52 patients per arm) at 11 hospitals in Japan. Secondary outcomes included causes of RBO, adverse events, and patient survival.

Results: TRBO did not differ significantly between the ARMS and covered SEMS groups (median, 251 vs 351 days, respectively; P=0.11). RBO as a result of biliary sludge or food impaction was observed in 13% and 9.8% of patients who received an ARMS and covered SEMS, respectively (P=0.83). ARMS was associated with a higher rate of stent migration compared with the covered SEMS (31% vs 12%, P=0.038). Overall rates of adverse events were 20% and 18% in the ARMS and covered SEMS groups, respectively (P=0.97). No significant between-group difference in patient survival was observed (P=0.26).

Conclusions: The current ARMS was not associated with longer TRBO compared with the covered SEMS. Modifications including addition of an anti-migration system are required to use the current ARMS as first-line palliative treatment of distal MBO (UMIN-CTR clinical trial registration number: UMIN000014784).