Patients with noncurative endoscopic resection (ER) (pT1a-MM/pT1b-SM) for esophageal squamous cell carcinoma (ESCC) have a certain risk of lymph node metastasis (LNM). Although the definite treatment strategy after ER is not recommended for pT1a-MM with negative lymphovascular invasion (LVI) because of its relatively low LNM risk, no additional treatment was selected in ＞90% of such patients in clinical practice. Conversely, additional treatment (esophagectomy or chemoradiotherapy) is recommended for pT1a-MM with positive LVI or pT1b-SM. Recently, risk stratification for metastatic recurrence in patients without additional treatment after noncurative ER for ESCC was established, and the efficacy of a novel treatment strategy, ER and selective chemoradiotherapy, for cT1bN0M0 ESCC was confirmed. Since many patients died of diseases other than ESCC, several studies focused on clinical prognostic factors, as well as pathological factors. Eventually, establishing a novel algorithm for treatment strategy of older patients with noncurative ER and developing a novel biomarker for predicting LNM or metastatic recurrence after noncurative ER will be anticipated in the field of ESCC.

We have reported two chemoprevention studies on preventing colorectal cancer (CC) without colorectal resection for familial adenomatous polyposis (FAP) using low-dose aspirin and intensive downstaging polypectomy (IDP) of colorectal polyps. Chemoprevention studies using low-dose aspirin, a 2×2 factorial, randomized, double-blind, placebo-controlled, multicenter trials were conducted at 11 centers in Japan. The results showed that low-dose aspirin safely inhibited the growth of colorectal polyps of ＞5.0mm at 8 months in patients with FAP, while mesalazine had little effect. Thus, low-dose aspirin may be a useful cancer chemoprevention drug for CC prevention in patients with FAP. The second study on IDP is a multicenter trial conducted for 5 years to demonstrate the safety of IDP. Although the IDP results confirm its safety and effectiveness in preventing CC, whether IDP prevents CC in the long-term in patients with FAP who did not undergo colorectal resection is unclear. Thus, we are preparing a registry for long-term follow-up. Based on these results, we believe that colorectal resection in patients with FAP can be prevented with appropriate endoscopic intervention and chemoprevention with low-dose aspirin.

We herein report two cases of asymptomatic esophageal anisakiasis diagnosed and treated endoscopically.

The first case was a 42-year-old man who underwent screening EGD at medical check-up, which revealed an Anisakis larva embedded in the esophageal mucosa proximal to the esophagogastric junction. The larva was successfully removed with a biopsy forceps. The patient had no symptoms either before or after the procedure.

The second case was an asymptomatic 55-year-old man who underwent EGD for screening purposes at medical check-up, which revealed an Anisakis larva embedding into the esophagus proximal to the squamocolumnar junction. The larva was removed using a biopsy forceps without developing any symptoms after the procedure.

Esophageal anisakiasis is rare but can be diagnosed with steady observation at EGD. In addition to removal of larva, education on the possible risk of the severe form of anisakiasis after consuming raw or undercooked fish seems to be important for its prevention in this asymptomatic patient group.

An 81-year-old man who underwent subtotal stomach-preserving pancreaticoduodenectomy was admitted to our hospital because of liver abscess. CT revealed a linearly shaped foreign body with bone density in the bile duct nearby the abscess. After treatment with antibiotics and percutaneous transhepatic abscess drainage, we removed the foreign body without complications using single balloon enteroscopy. The foreign body was determined to be a fishbone. Foreign body migration to the bile duct after pancreaticoduodenectomy is rare and occasionally causes liver abscess, cholangitis, and bile duct stones. In symptomatic cases, removing the foreign body from the bile duct should be considered to control infection. For removing the foreign body from the bile duct after pancreaticoduodenectomy, balloon enteroscopy is minimally invasive with a high success rate. We consider balloon enteroscopy as a first-line treatment option for symptomatic fishbone migration in the bile duct after pancreaticoduodenectomy.

Case 1 is a 65-year-old man admitted to our hospital with abdominal distension and vomiting. Small intestinal ileus was found on abdominal CT. Dietary ileus was suspected because the nasal ileus tube was invalid and CT imaging eventually showed movement of the occlusion origin from the jejunum to the ileum. Because of difficulties in colonoscopy, the foreign body was removed by laparoscopically-assisted endoscopy. The content was shiitake mushrooms. Case 2 is a 77-year-old man who visited our hospital with complaints of abdominal distension and vomiting. Abdominal CT showed small intestinal ileus with a high-density mass. Based on the clinical course, dietary ileus was suspected and a colonoscopy was performed. A konjac mass was found at the end of the ileum and removed endoscopically. Both patients had no organic stenosis in the intestinal tract; although they had missing teeth, they did not use dentures. Detailed interviews and CT imaging were considered important for the definitive diagnosis of dietary ileus.

A 74-year-old woman with chronic diarrhea and abdominal pain visited a primary care physician. The patient was suspected ischemic colitis (IC) by colonoscopy. After 3 months, she was referred to our department because the symptoms did not improve. Colonoscopy revealed edematous/granular mucosa with extensive ulcer in the cecum (descending colon), and IC was suspected. However, we diagnosed collagenous colitis (CC) based on medical history of lansoprazole administration and clinical symptoms. The diagnosis of CC was confirmed by biopsy of the longitudinal ulcers of the sigmoid colon. On day 7, her diarrhea became mild after lansoprazole was discontinued, and the ulcer disappeared on endoscopy. Although CC with extensive ulcer is extremely rare, there are cases that require differentiation from IC as endoscopic appearance and should be attended.

When a post-resection ulcer is expected to involve more than three-fourths of the esophageal circumference, it is advisable to consider preventive measures against stenosis, such as submucosal triamcinolone injection, as such lesions are associated with a high risk of stenosis following endoscopic resection.

In the case of stricture development, endoscopic balloon dilation (EBD) is performed. To prevent perforation during EBD, it is recommended to use a 12-15 mm balloon and gradually increase the pressure to 8 atm over 4 min. For severe stenosis, a 10-12mm balloon is used.

In the event of a perforation during EBD, fasting and administrating antibiotics are necesssary. If conservative treatment fails to show any improvement, surgical drainage should be considered.

With advances in endoscopic equipment and increased awareness among endoscopists, early-stage neoplastic lesions proximal to the appendiceal orifice are often detected. Recently, ESD has become a common treatment in the colorectal field, with high en-bloc resection rates, and difficult cases can be resected using appropriate devices and ESD strategies. The appendiceal orifice is considered a challenging site because of its anatomical structure, and the risk of perforation is high because of the high frequency of submucosal fibrosis and thin muscle layer. Therefore, it is necessary to consider in advance the endoscopic treatment indications and be proficient in the technique. Additionally, appendicitis may occur after endoscopic treatment of lesions near the appendiceal orifice, and its characteristics should be understood. This study describes the endoscopic treatment indications and methods, focusing on ESD, for lesions proximal to the appendiceal orifice (including cases of extension within the orifice). The safety and efficacy of ESD may improve with the development of new treatment methods eventually.

One concern associated with pancreatic diseases is the poor prognosis of pancreatic cancer. Even with advances in diagnostic modalities, risk stratification of premalignant lesions and differentiation of pancreatic cysts are challenging. Pancreatic lesions of concern include intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystadenomas, pseudocysts, and retention cysts, as well as cystic degeneration of solid tumors such as solid pseudopapillary neoplasms and pancreatic neuroendocrine neoplasms. Pancreatic juice obtained during endoscopic retrograde cholangiopancreatography has previously been used for the detection of KRAS mutation. Recently, duodenal fluid, which can be obtained during the relatively minimally invasive procedures of endoscopic ultrasound (EUS) and esophagogastroduodenoscopy, and cyst fluid collected by EUS-guided fine-needle aspiration (FNA) were used for molecular biological analysis. Furthermore, advanced analytic methods with high sensitivity were used for the detection of single and multiple markers. Early detection of malignant pancreatic tumors and risk stratification of premalignant tumors can be performed using duodenal fluid samples with a single marker with high sensitivity. Technological advances in simultaneous detection of multiple markers allow for the differentiation of cystic pancreatic tumors. One thing to note is that the clinical guidelines do not recommend pancreatic cyst fluid and pancreatic juice (PJ) sampling by EUS-FNA and endoscopic retrograde cholangiopancreatography, respectively, in actual clinical practice, but state that they be performed at experienced facilities, and duodenal fluid sampling is not mentioned in the guidelines. With improved specimen handling and the combination of markers, molecular markers in PJ samples may be used in clinical practice in the near future.