Recently, the lives of the Japanese people have been affected by the rapid increase in the incidence of colorectal cancer, and advances in the treatment and prevention of this disease are urgently needed. Many epidemiological studies have demonstrated that physical inactivity, a Western-style diet and subsequent obesity increase the risk of colorectal cancer. Furthermore, it is noteworthy that obesity, especially visceral fat accumulation, induces the abnormal secretion of adipocytokines, which are secreted from adipose tissue. Epidemiological and molecular biological studies have shown an association between adipocytokines, such as adiponectin and leptin, and the incidence/progression of colorectal cancer. Thus, the mechanisms underlying the promotion of colorectal carcinogenesis by obesity have gradually become clear. Recently, studies concerning the chemoprevention of colorectal cancer have made progress, and it is desirable that safe and effective chemopreventive drugs are identified.

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We compared pharyngeal anesthesia with viscous lidocaine solution and lidocaine candy for the reduction in the degree of pain during and after upper GI endoscopy (GIE) gastroscopy A total of 248 patients who underwent GIE were randomized into the lidocaine candy group (candy ; 126 patients) or the viscous lidocaine solution group (viscous ; 122 patients). The patients were asked to assess using a visual analogue scale (VAS) how uncomfortable they were under the following conditions : while pharyngeal anesthesia was in the mouth ; immediately after pharyngeal anesthesia left the mouth ; during GIE ; and after GIE. We statistically compared the VAS score between the 2 groups. Results were as follows : with pharyngeal anesthesia in the mouth, candy group 12.7 (9.3-16.1) vs. viscous group 40.1 (35.6-45.6) (P<0.001) ; immediately after pharyngeal anesthesia left the mouth, candy group 14.3 (10.6-18.0) vs. viscous group 34.0 (29.0-39.0) (P<0.001) ; during GIE, candy group 48.9 (42.6-55.2) vs. viscous group 58.9 (52.9-64.9) (P<0.05 ; and after GIE, candy group 13.9 (10.2-17.6) vs. viscous group 26.4 (21.1-31.7) (P<0.001). We conclude that pharyngeal anesthesia using lidocaine candy reduced discomfort to a greater degree than viscous lidocaine solution under all conditions examined.

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A 38-year-old Peruvian woman visited our outpatient unit with the chief complaints of heartburn and epigastralgia. ¹⁴C urea breath test was Helicobacter pylori (H. pylori) positive. Esophagogastroduodenoscopy, capsule endoscopy and colonoscopy revealed small whitish nodules extending from the gastric antrum to the end of the ileum. Although all of the biopsy specimens from nodules revealed lymphoid follicles, immunohistological examinations showed that the nodules in the stomach were reactive lymphoid hyperplasia associated with nodular gastritis while the nodules in the bulb, descending duodenum, and the ileum were follicular lymphoma (FL). Our final diagnosis was that only the gastric nodules were reactive lesions, often called nodular gastritis associated with H. pylori infection, but that the other nodules were FL.

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We experienced two women, aged 39 years and 46 years, who presented with abdominal pain. In each case, intussusception caused by a cystic tumor was suspected based on abdominal computed tomography. In each case, reduction of the intussusception was easily achieved by gastrografin enema and carbon dioxide insufflation by colonoscopy. From the endoscopic view, the tumors had a submucosal tumorlike appearance in the cecum. We diagnosed the tumors in both patients as mucoceles of the appendix, and ileocecal resections were performed. The pathological diagnosis of the resected specimens was mucinous cystadenoma of the appendix. Intussusception caused by mucinous cystadenoma of the appendix is very rare, and we should keep this condition in mind in the case of intussusception caused by a cystic tumor.

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A 76-year-old man without symptoms had undergone a colonoscopy 3 years previously during which a semipedunculated submucosal tumor of 30 mm in diameter was found on the ileocecal valve. Since lymphangioma or lipoma was suspected on the basis of endoscopic findings, routine follow-up was performed. In comparison with the size of the tumor a year earlier, colonoscopy and computed tomography indicated that the tumor had enlarged. Since endoscopic excision was considered difficult to perform safely due to the large tumor size, laparoscopic-assisted ileocecal resection was performed. The tumor was 30×25 mm in size, and there were multiple cystic lesions in the submucosa. Histological diagnosis was lymphangioma. Lymphangioma on the ileocecal valve is very rare, and endoscopic excision is mainly performed for this lesion. Based on postoperative histopathological findings, we were able to determine that endoscopic excision would have been appropriate for this lymphangioma on the ileocecal valve.

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A 64-year-old woman was admitted to the hospital because of her recent diagnosis of advanced cancer of the ascending colon. She had a past surgical history of endometrial cancer at the age of 49, rectal cancer at the age of 57, and transverse colon cancer at the age of 59. Her father had gastric cancer, her brother had renal cancer, her daughter had ovarian cancer, and her son had brain cancer (glioblastoma). A 15-mm depressed lesion was detected by a follow-up colonoscopy that was performed annually after the transverse colon surgery. Pathological examination of biopsy specimens of the lesion revealed adenocarcinoma, and laparoscopic right hemicolectomy was performed (Stage IIIB, pT3N0M0). Testing for mismatch-repair genes revealed a nonsense mutation in the MSH2 gene ; she was diagnosed with Lynch syndrome. This case suggests that colonoscopic surveillance of patients with Lynch syndrome should include examinations sufficiently thorough to detect rapid-growing lesions at an early stage.

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A 71-year-old woman diagnosed with obstructive jaundice associated with common bile duct stones was referred to our hospital. ERCP revealed hemobilia and distal bile duct stenosis, but biliary cytology and examination of biopsy specimens revealed no malignant cells. As cholangiocarcinoma could not be ruled out, a pylorus-preserving pancreatoduodenectomy was performed. No histopathological evidence of malignancy was revealed, while adenomyomatous hyperplasia was observed in the ampullary bile duct. AA type amyloid deposits and vasculitis were found within the vascular walls of the pancreatic head, gall bladder, and extrahepatic duct. We concluded that the hemobilia was associated with amyloidosis secondary to rheumatoid arthritis.

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We experienced 2 cases of chronic pancreatitis with proximal migration of an endoscopic pancreatic stent (EPS). Case 1 was a 52-year-old woman who had idiopathic pancreatitis and had undergone EPS placement for stenosis of the main pancreatic duct. Case 2 was a 45-year-old man who had alcoholic pancreatitis and had undergone EPS placement for stenosis of the main pancreatic duct and pancreatic stones. In both cases, EPS exchange was performed for acute exacerbation of the pancreatitis with stent occlusion. However, the EPS migrated into the main pancreatic duct at the time of stent removal in case 1 and during replacement in case 2. We initially used a rat-tooth forceps, balloon catheter, and basket catheter for retrieving the migrated EPSs. However, stent retrieval was unsuccessful. Subsequently, using wire-guided biopsy forceps, we could grasp the distal end of the migrated EPS and successfully retrieve it. Endoscopic pancreatic stenting is a minimally invasive and effective option for painful chronic pancreatitis with stenosis of the main pancreatic duct, but complications, including stent migration, may occur during this procedure. Our cases suggested that wire-guided biopsy forceps can be used to pass through the narrow segment of the main pancreatic duct to grasp the distal end of the EPS and that the axes of the forceps and EPS can be set using a guide wire. Therefore, we concluded that wire-guided biopsy forceps should be useful for grasping and retrieving stents with proximal migration.

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A 61-year-old man was admitted to our hospital for fever and abdominal bloating. A CT scan demonstrated massive ascites in the abdominal cavity and a tumor of the uncus of the pancreas. The cause of the ascites was an obstruction within the pancreas because of high amylase level. EUS showed that the tumor of the pancreatic uncus was 18 mm in diameter. ERCP revealed stenosis of the main pancreatic duct (MPD) with a pseudocyst on the distal side and communication between the pseudocyst and abdominal cavity. The patient underwent ENPD and pancreatic stent placement based on the diagnosis of pancreatic cancer by EUS-FNA. The pancreatic ascites has disappeared.

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Autoimmune pancreatitis (AIP) is a unique form of pancreatitis in which autoimmune mechanisms are suspected to be involved in its pathogenesis. AIP is currently diagnosed based on the International Consensus Diagnostic Criteria (ICDC). Although the use of resected or core biopsy specimens are recommended for the histological classification according to the ICDC, it is difficult to collect adequate pancreatic biopsy specimens for detailed examination. With the widespread use of EUS-guided FNA (EUS-FNA) cytology and histology, these have become essential modalities for the diagnosis of pancreatic diseases. We here present tips for the diagnosis of AIP by EUS-FNA. Because adequate collection of pancreatic tissue depends on how fast the needle is moved within the pancreas, it is crucial to insert the aspiration needle as quickly as possible. For this purpose, a spring-loaded biopsy needle or a manual aspiration needle such as the Boston Expect, which has a strong needle stopper and a stiff needle, is useful. Adequate processing of histological specimens is another important point. The aspirated tissues are pushed out on a glass slide using a syringe. Tubifex-like pieces of tissue in the blood are picked up and transferred to another formalin-filled dish. The pancreatic tissue is trimmed with disposable 18-G needles and transferred to another formalin-filled container for pathological examination. We usually can obtain histological samples adequate for the assessment of IgG4-positive plasma cells and obliterative phlebitis. EUS-FNA provides adequate histological samples for the diagnosis of AIP and therefore may help to increase the value of ICDC in diagnosing AIP as well as determining the type of AIP.

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Endoscopic ultrasonography (EUS) can produce vertical cross-sectional images of gastrointestinal lesions and is therefore used to estimate the depth of cancer invasion and to qualitatively diagnose submucosal tumors (SMTs) in patients with colorectal disease. EUS of the colorectum can be performed with the use of dedicated devices or with an ultrasound probe (USP). The latter is mainly used. USPs are available in various frequencies, such as 12 MHz and 20 MHz, and are selected on the basis of the macroscopic appearance of lesions and the purpose of the examination. Some USPs can be used for three-dimensional scanning. Before EUS, adequate bowel preparation is essential. EUS is mainly performed using the de-aired water repletion technique. The normal colorectal wall is basically depicted as a five-layer structure. The depth of invasion of colorectal cancer on EUS is expressed as the deepest layer in which the wall structure has been destroyed by the tumor. SMTs are diagnosed on the basis of tumor localization and the internal echo pattern on EUS. It is most important to vertically scan lesions when diagnosing colorectal disease on EUS. However, clear cross-sectional images are sometimes precluded by lesion location or height. Appropriate EUS devices should therefore be selected, and improved examination techniques are necessary.

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[in Japanese]

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