Duodenal adenomas are observed as whitish, flat elevated lesions. The features of mucosal carcinoma are redness, large size, irregular surface, and obscure mucosal pattern on magnifying narrow-band imaging (NBI). It is difficult to make a differential diagnosis between adenoma and carcinoma, and the accuracy of endoscopy or biopsy is reported to be 68-78％. Biopsy may induce submucosal fibrosis, which could hamper subsequent endoscopic resection. Duodenal endoscopic submucosal dissection (ESD) has a high complete resection rate, but is associated with a high risk for perforation. There is a high risk for post-operative adverse events among patients with a duodenal mucosal defect due to exposure to bile and pancreatic juice. It is desirable to perform prophylactic clip closure after duodenal ESD.

【Background and Objective】We conducted a retrospective analysis to investigate the efficacy and safety of self-expandable metallic stent (SEMS) placement in terms of properties of the mechanical stent. 【Methods】We examined 42 patients with advanced esophageal carcinoma who underwent placement of a SEMS in our department between January 2008 and August 2016. We classified them according to the absence of radiotherapy, type of SEMS, and efficacy (dysphagia score, period until drinking and dietary intake, overall survival time), and compared adverse events between the groups. 【Results】 The median age was 67.5 years old, and the primary tumor was located at the middle thoracic esophagus in 27 cases (64.2％). There were no significant differences in efficacy and safety between those who did or did not undergo radiation treatment. Although there were no significant differences in efficacy and the incidence of adverse events among the different SEMS types, the incidence of serious adverse event (SAE) was significantly different according to the type of SEMS (P＜0.01). 【Conclusion】 For the effectiveness and safety of SEMS placement, an important consideration is not only whether or not radiotherapy was administered, but also stent selection. To place the SEMS safely, it is important to select a suitable stent for the patient’s condition taking mechanical properties of the SEMS into account.

We performed endoscopic submucosal dissection (ESD) for multiple superficial esophageal cancers in a case coexisting with esophageal achalasia. The patient was a 55-year-old man who suffered from dysphagia for the past 18 years. He was diagnosed as having esophageal achalasia by various imaging examinations that revealed the morphology and function of the esophagus. Then, screening esophagogastroduodenoscopy detected multiple superficial esophageal cancers at the upper part (1 lesion) and the middle part (5 lesions) of the esophagus. All esophageal lesions at the upper and middle parts of the esophagus in the patient who had already been diagnosed with esophageal achalasia, were successfully removed by ESD. Pathological examination showed squamous cell carcinoma for three lesions and high-grade intraepithelial neoplasia for the other three lesions. Immunostaining for p53 showed positivity in not only cancer cells but also non-cancerous cells. In this case, it is likely that prolonged mechanical and chemical irritations due to achalasia led to a p53 mutation and resulted in the development of cancer. It is important to carry out careful long-term follow-up for patients with achalasia to detect esophageal cancer as soon as possible. We herein report such a patient with a review of the relevant literature.

A 29-year-old man visited a local clinic with a stomachache. He was diagnosed with Helicobacter pylori (HP) infection by esophagogastroduodenoscopy, and HP eradication therapy was started at that clinic. However, one day after starting HP eradication therapy, he developed severe abdominal pain and presented to the emergency room of our hospital. He was admitted to our hospital for further examination and treatment. During the hospitalization, purpura appeared on his lower extremities. Esophagogastroduodenoscopy and colonoscopy revealed diffuse mucosal erosions of the esophagus, stomach, duodenum, ileum, and colon. Histological examination of biopsy specimens of the skin and duodenum led to the diagnosis of IgA vasculitis. After treatment with prednisolone, his abdominal symptoms and purpura successfully subsided. In conclusion, we experienced a patient who initially had typical endoscopic findings of IgA vasculitis in the upper and lower gastrointestinal tracts that changed over time. Of note, he developed very rare esophageal lesions.

A 76-year-old woman presented to the emergency room of our hospital with the chief complaints of fever and epigastralgia. She had elevated inflammation with an elevated blood C-reactive protein level of 13.7 mg/dL. Contrast computed tomography, magnetic resonance imaging and endoscopic ultrasound revealed multilocular cysts with 70-mm capsules in the pancreatic tail. The lesions had a cyst-in-cyst appearance, and 10-mm mural nodules with a contrast effect were seen in the cysts. Endoscopic retrograde pancreatography showed communication of the cysts with the pancreatic duct. Examination of the cyst fluid showed an increased number of neutrophils and positivity for Escherichia coli by bacterial culture. Based on the above findings, the diagnosis of pancreatic mucinous cystadenocarcinoma with bacterial infection was made, and distal pancreatectomy was performed. Pathologically, an ovary-like interstitium was seen in the cyst wall, and the mural nodules were adenocarcinoma. When dealing with infectious pancreatic cysts, it is necessary to consider treatment methods while keeping in mind the possibility of neoplastic cysts.

High resolution esophageal manometry (HREM) in which solid state sensors are located one centimeter apart on the catheter has been developed. The Chicago classification is a newly proposed classification of esophageal motility disorders. Esophageal motility disorders are systemically classified in the Chicago classification and a diagnostic schema in the Chicago classification allows physicians to diagnose esophageal motility disorders by inputting values of parameters. Esophageal achalasia is characterized by impaired swallow-related esophago-gastric junction relaxation and absence of esophageal peristalsis. Esophageal achalasia is divided into three types and treatment outcomes are different among these types. Attention should be paid to different cut-off values of parameters in the Chicago classification between ManoScan and other systems with a Unisensor catheter. In addition, artifacts sometimes affect values of parameters measured by HREM; therefore, it is important to diagnose esophageal motility disorders comprehensively in combination with other tests such as esophagography.

Strictures of the small intestine are a significant complication in patients with Crohn’s disease. Their treatment remains a major challenge. Surgical resection cannot cure Crohn’s disease. Multiple resection of strictures may lead to short bowel syndrome. The development of balloon-assisted enteroscopy has enabled balloon dilation for strictures in the deep small bowel. Because balloon dilation can be repeatedly performed for recurrence of strictures, it may avoid or postpone the need for surgery. In this article, we introduce strategies and devices for endoscopic balloon dilation therapy for Crohn’s disease strictures.

Using endoscopic ultrasonography (EUS), it is practicable to diagnose subepithelial lesions (SEL) with originating layer, echo level, and internal echo pattern etc. Lipoma, lymphangioma, and cyst have characteristic features; therefore, there is no need for endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA).

Ectopic pancreas and glomus tumors, which originate from the third and fourth layers, are frequently seen in the antrum.

However, ectopic pancreas located in the fundus or body is large and originates from the third and fourth layers (thickening of fourth layer). Each subepithelial lesion has characteristic findings.

However, imaging differentiation of tumors originating from the fourth layer is very difficult, even if contrast echo is used.

Therefore, EUS-FNA should be done in these tumors, but the diagnostic yield for small lesions is not sufficient for clinical demands. Generally, those tumors, including small ones, should be first followed up in 6 months, then yearly follow up in cases of no significant change in size and features. When those tumors become larger than 1-2 cm, EUS-FNA is recommended. Furthermore, unusual SEL and SEL with malignant findings such as nodular, heterogeneous, anechoic area, and ulceration indicate EUS-FNA. Cap-attached forward-viewing echoendoscope is very helpful for EUS-FNA of small SEL.