A 70-year-old man was rescued by bloody stool and transient loss of consciousness. Lower gastrointestinal endoscopy showed a type 1 lesion in the ascending colon and a type 2 lesion in the sigmoid colon.

Right hemicolectomy and sigmoid resection were performed for ascending colon and sigmoid colon cancer. The ascending colon was histopathologically a mucinous carcinoma, pT4bN0M0 pStageII.

In the sigmoid colon, squamous cell carcinoma-like tissue and adenocarcinoma-like tissue that were mixed on HE staining, and CK7-positive, CK20-negative, CDX2-negative, CK5/6-positive on immunostaining were diagnosed to be pT3N2M0 pStageIIIB.

Histologically, more than 90% of colorectal malignancies are adenocarcinomas, and adenosquamous carcinomas are reported to account for 0.025% to 0.05% of all colorectal malignancies. In this report, we describe a case of double cancer involving colorectal squamous cell carcinoma and mucinous carcinoma.

A 71-year old man with right hypochondriac pain was referred to our hospital for suspicion of liver abscess. Enhanced abdominal CT showed a 40 mm liver abscess with a needle-like structure penetrating the intestinal wall to the liver. We suspected that the ingested foreign body had penetrated the afferent loop of Roux-en Y reconstruction and caused liver abscess. We performed double-balloon endoscopy (DBE) and succeeded in removing the foreign body; bamboo skewer. We administrated antibiotics and performed percutaneous abscess drainage, and then he became afebrile. There are no reports of liver abscess due to the penetration of an ingested foreign body migrated to the afferent loop blind end. In this case, DBE was effective in removing a foreign body in a postoperative patient. We must consider the possibility of unexpected movement of ingested foreign body in a patient with surgically altered gastrointestinal anatomy.

The case is a 79-year-old man. Emergency ERCP was performed due to severe acute cholangitis, and stone extraction was performed after EST. On the 6th postoperative day, tarry stool was observed. Emergency upper endoscopy showed a large amount of blood clot adhered to the Vater's ampulla. It was difficult to secure a visual field, and a fully covered metallic stent was placed to perform compression hemostasis. The procedure completed without any complications. Ten days later, the stent was removed by the snare and the patient was discharged with good progress. Compression with a metallic stent is effective for severe post-EST bleeding.

A 62-year-old male patient was referred to our hospital because of multiple pancreatic mass lesions. Contrast-enhanced computed tomography revealed multiple hypovascular lesions in the pancreas. Endoscopic ultrasonography revealed vague boundary, low echoic multiple mass lesions, and a duct-penetrating sign. We performed endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA). Histopathological examination revealed a typical lymphoplasmatic sclerosing pancreatitis. Subsequently, we made a diagnosis of multifocal type 1 autoimmune pancreatitis (AIP). After corticosteroid administration, the multiple mass lesions in the pancreas and kidney completely disappeared. AIP is difficult to distinguish from other diseases when it shows multifocal mass lesions in the pancreas. A comprehensive diagnosis is needed on the basis of other organ involvements, serum IgG4 level, and pathological findings from EUS-FNA.

The most major cause of hilar bile duct stenosis is the malignant disease, but there are some benign causes and that makes the differentiation very difficult. We experienced a case of chronic cholecystitis to case a hilar bile duct stenosis which was difficult to differentiate from the gallbladder cancer.

We performed contrast CT (Computerized Tomography), ERCP (Endoscopic Retrograde Cholangiopancreatography), EUS-FNA (Endoscopic Ultrasound-Fine Needle Aspiration), PET CT (Positron Emission Tomography CT). From the results of these inspections, we diagnosed the case as chronic cholecystitis and operated a laparotomy cholecystectomy. The pathological diagnosis was chronic cholecystitis, and that showed we could raise the probability of diagnosis by performing some inspections and we could avoid the enlarge operation of liver resection. In conclusion, we recommend to combine some inspections before having the operation of hilar bile duct stenosis.

A 60-year-old male developed symptomatic pancreatic duct stricture due to pancreatic metastasis from lung cancer. Transpapillary pancreatic duct drainage was challenging; hence, pancreatic duct drainage was successfully performed using the endoscopic ultrasonography-guided rendezvous procedure (EUS-RV). The guidewire was navigated to the duodenum, beyond the stricture site in the main pancreatic duct. The procedure was successful as the guidewire was maintained in a U-shape by securing the distance between the puncture and pancreatic stricture sites. By replacing the catheter with a tapered one, guidewire seeking was simplified. However, the EUS-RV technique requires advanced skills. It is important to note that completing the procedure often requires more than one session. The formation of a pancreatic duct-gastrointestinal fistula should be prioritized; transpapillary stent placement can be performed through RV route later.

A 79-year-old male patient was referred to our department for the evaluation of a pancreatic body tumor, which was detected incidentally on contrast-enhanced computed abdominal tomography. An EUS-FNA was performed for the tumor via the trans-gastric approach. Based on the findings, pancreatic adenocarcinoma was diagnosed. The patient underwent a distal pancreatectomy and a splenectomy. At postoperative 18 months, he experienced upper abdominal pain and underwent gastroendoscopy, which revealed a submucosal tumor on the posterior gastric wall and needle tract seeding of the pancreatic cancer. He received chemotherapy, but his general condition gradually deteriorated, and he died at postoperative two years due to infectious pneumonia. Needle tract seeding is a serious complication of EUS-FNA and should be seriously considered as a possibility in patients who have undergone an EUS-FNA via the gastric-wall approach. Furthermore, the indications for EUS-FNA should be weighed carefully if a pancreatic tumor, especially in the pancreatic body or tail, has already been diagnosed via another modality.

A 74-year-old man with an expanding pancreatic cyst was referred to our hospital for the purpose of close examination and treatment. Contrast-enhanced computed tomography revealed a 9-mm dilated main pancreatic duct and a multilocular cystic lesion with communication with the main pancreatic duct at the pancreatic head. Endoscopic ultrasonography revealed no apparent neoplastic lesions inside. No apparent neoplastic lesion was found on endoscopic retrograde cholangiopancreatography and pancreaticoscopy. The patient was considered to be a branched intraductal papillary mucinous neoplasm (IPMN) with dilatation of the main pancreatic duct. Although the type of IPMN is sometimes difficult to determine, we could classify the type using pancreaticoscopy.

The patient was a woman in her 70s. She was referred to our hospital with epigastric pain and vomiting. She was diagnosed with acute purulent cholangitis and gallstone pancreatitis. An emergency ERCP was performed, which revealed a common bile duct stone. After EST small incision, an EBD tube was placed. Her symptoms improved after conservative treatment. After 3 months, another ERCP was performed for stone removal, during which we found that the stent was penetrating the Vater's papilla. The stent was removed using forceps. Cholangiography was performed from the Vater's papilla and the penetrating part, and the common bile duct stone was confirmed. The calculus was completely removed through the Vater's papilla. Although a complication rate of 0.994% associated with ERCP-related procedures has been reported in a nationwide survey, there was no report of Vater's papilla penetration. We had performed ERCP in 450 patients for the past 3 years and encountered only 2 patients (0.4%) with Vater's papilla penetration. In both the patients, the same type of straight side flap was placed after EST small incision for cholangitis treatment.

A 65-year-old man underwent Billroth II surgery and was referred to our department for jaundice. Our diagnosis was cancer of the pancreatic head, so we placed a bare metallic stent in the bile duct. We performed endoscope because of melena but findings were unremarkable. Laboratory investigations revealed anemia and inflammation. Dynamic computed tomography showed no aneurysmor contrast extravasation. Endoscope revealed hemobilia, so we performed endoscopic retrograde cholangiopancreatography and replaced a plastic stent in the bile duct for drainage. We used a gastroscope to observe the lumen of the bile duct, noted oozing from the metallic stent in the duct distally, and achieved hemostasis by placing a covered metallic stent. This case of hemobilia was successfully confirmed using endoscope.

A woman in her 60's visited our hospital complaining abnormality in medical examination. Pancreatic cysts, adenomyomatosis, a gallbladder stone, and thickened gallbladder wall were detected using abdominal ultrasonography. Detailed investigations, including ERCP, revealed a non-dilated pancreaticobiliary maljunction, with branch-type IPMN and cholecystectomy was performed. Pathological examination revealed adenomyomatosis of the gallbladder at the bottom and cholesterosis in the gallbladder wall. Biliary carcinoma occurs in 42.4% of non-dilated bile duct-pancreatic-biliary junction abnormalities, and 88.1% of these cases are gallbladder carcinoma; therefore, prophylactic cholecystectomy is recommended. However, because this case was diagnosed in an elderly patient, surgery was performed immediately after confirming the absence of malignancy in the biliary system by using EUS and biliary cytology. In addition, the patient also has IPMN, which is considered to be a high risk for pancreatic cancer development. Frequent follow-up of the patient's pancreatic-biliary system function is required.

A 67-year-old male with pancreatic cancer with hepatic metastasis and peritoneal dissemination had been treated with chemotherapy and had regular percutaneous ascites drainage about every two weeks. He developed anorexia and a new localized ascites was created in front of the pancreas, which compressed the stomach. We suspected pancreatic fistula, and EUS-guided placement of plastic pigtail stents for the drainage was performed. After the treatment, the symptom was improved immediately. Ascites did not recur until tumor death.

There are few reports of EUS-guided drainage for localized malignant ascites and no cases from pancreatic cancer. EUS-guided drainage is a safe and highly curative treatment, and is a useful treatment for symptomatic patients with localized malignant ascites.

We report the japan's first experience of proximal release type colonic stent designed at our department, for malignant stenosis of the lower rectal stricture by peritoneal dissemination of gastric cancer. A 50s female developed malignant rectal obstruction during chemotherapy for peritoneal dissemination following the surgery for gastric cancer, and she was referred to our hospital for colonic stent placement. On admission, her colorectal obstruction scoring system (CROSS) score was 0, and decompression had been performed by transanal urethral balloon catheter placement at the former institution. For the colonic stent placement, via the same catheter, a 0.035 inch Fr RevoWave ultra-hard guidewire was placed, and after endoscopic observation and fluoroscopic imaging, a marking clip was placed, and then a Niti-S colonic stent- proximal stent 22×70 mm was placed. There were no complications observed during stent placement, and the following day, oral intake was started and transferred to her previous clinic for ongoing chemotherapy. For the stent placement for rectal stricture, if the distal edge of the stent locate touch to the dentate line, it willhighly likely cause of pain, and thus it is important to select the appropriate stent length while taking into account the length of stenosis as well as the distance from the anal verge. In addition, it is also important that the stent placement site is neither excessive nor insufficient. The presently developed proximal release type stent enables the distal side of the stent position to accurately match the marking clip, and we believe that it will be useful in stent placement for malignant stenosis of the lower rectum. The ColoRectal Obstruction Scoring System (CROSS) of the Japan Colonic Stent Safe Procedure Research Group is available to the public on their home page (http://colon-stent.com). This group recommends the CROSS, an objective score, to evaluate the patient's condition preoperatively, and to indicate and evaluate decompression methods.