Factors that affect the development of acute hemorrhagic rectal ulcer syndrome and rebleeding.

Objectives: Acute hemorrhagic rectal ulcer syndrome (AHRUS) causes massive bleeding and often recurrent rebleeding from rectal ulcers that form immediately above the dentate line. This study aimed to determine the clinical background and risk factors contributing to rebleeding in patients with AHRUS and the most appropriate method of hemostasis treatment. Methods: This retrospective study included 93 patients diagnosed with AHRUS at Showa University Fujigaoka Hospital, Japan, between April 2009 and November 2018. Information on clinical background factors, endoscopic findings, and hemostasis was obtained from medical records. The relationship with episodes of rebleeding was analyzed by multivariate logistic regression analysis. Results: The median age was 79 years, and 84 patients (90%) had a performance status of grade 2 or higher. The patients had multiple background factors, with a median number of 5 per patient. The background factors could be classified into two major factors: those related to arteriosclerosis and those related to delayed wound healing.In the multivariate analysis, significantly more rebleeding occurred in patients with active bleeding during the initial endoscopy (odds ratio 4.88, 95% confidence interval 1.80-14.46, p = 0.003); significantly less rebleeding occurred in patients for whom hemostasis was first performed by clipping (odds ratio 0.30, 95% confidence interval 0.09-0.88, p = 0.035). Conclusions: In bedridden older individuals with poor general health, multiple combinations of arteriosclerosis-related factors and protracted wound healing factors can induce AHRUS. We strongly recommend performing hemostasis via the clipping method on suspected bleeding points, including active bleeding sites, in AHRUS.

Acceptability of endoscopic submucosal dissection for sessile serrated lesions: comparison with non-sessile serrated lesions.

Background and study aims Sessile serrated lesions (SSL) are major precursor lesions of serrated pathway cancers, and appropriate treatment may prevent interval colorectal cancer. Studies have reported the outcomes of endoscopic mucosal resection (EMR) for SSL; however, there are insufficient reports on endoscopic submucosal dissection (ESD). We examined the characteristics and outcomes of SSL and compared them to those of non-SSL in ESD. Patients and methods We reviewed 370 consecutive cases in 322 patients who underwent colorectal ESD between January 2016 and March 2020 at our hospital. There were 267 0-IIa lesions that were stratified into 41 SSL and 226 non-SSL (intramucosal cancer, adenoma) cases. We used propensity matching to adjust for the variances in the factors affecting treatment between the SSL and non-SSL groups. Results In the baseline cases, young women and proximal colon tumor location were significantly more common in the SSL group. There were no statistically significant differences between the SSL and non-SSL groups in terms of en bloc resection rate (97.6 % vs. 99.6 %; P  = 0.28), R0 resection rate (92.7 % vs. 93.4 %; P  = 0.74), perforation (0 % vs. 0.9 %; P  > 0.99), and postoperative bleeding (2.4 % vs. 1.8 %; P  = 0.56). Thirty-eight pairs were matched using propensity score, and the median dissection speed (12 vs. 7.7 cm 2 /h; P  = 0.0095) was significantly faster in the SSL than in the non-SSL group. Conclusions ESD for SSL was safely performed, and SSL was smoother to remove than non-SSL. ESD might be an acceptable endoscopic treatment option for SSL.

Efficacy and suitable indication of colorectal endoscopic submucosal dissection using a balloon-assisted endoscope.

BACKGROUND AND AIM: Cases of colorectal endoscopic submucosal dissection (ESD) with poor maneuverability are often encountered. We aimed to evaluate the efficacy of balloon-assisted endoscopy (BAE) for such cases. METHODS: We confirmed maneuverability preoperatively in 400 consecutive cases of colorectal ESD performed at a single center from April 2011 to April 2018. A total of 83 deep colon cases judged as having poor maneuverability were retrospectively reviewed; 54 cases underwent BAE with a single balloon endoscope (group B), and 29 cases underwent conventional procedures without BAE (group C). Tumor size, procedure duration, dissection speed, en bloc resection rate, histology, and associated complications were compared between groups. RESULTS: The mean tumor size, tumor invasiveness, fibrosis, and complications did not differ between groups. Although the en bloc resection rate did not differ (both 98%), the groups significantly differed with regard to the R0 resection rate (B: 96%; C: 83%; P = 0.048). Overall, the procedure duration (B: 51 min; C: 70 min; P = 0.17) and dissection speed (B: 19.4 mm2/min; C: 17.4 mm2/min; P = 0.13) were not significantly different between groups. However, the dissection speed for lesions in the cecum/ascending colon was significantly faster in group B than in group C (B: 22.3 mm2/min; C: 11.3 mm2/min; P = 0.037). CONCLUSIONS: In cases of colorectal ESD with poor maneuverability, the use of BAE contributed to an improvement in the R0 resection rate. In addition, BAE contributed to a quicker dissection speed for lesions located in the cecum/ascending colon.

Mucinous Cystic Neoplasms Lined by Abundant Mucinous Epithelium Frequently Involve KRAS Mutations and Malignant Progression.

BACKGROUND: Pancreatic and hepatic mucinous cyst neoplasms (MCNs) have a malignant potential, but indolent MCNs are not uncommon. MATERIALS AND METHODS: The pathological and genetic characteristics of resected MCNs (n=15) categorized by the amount of mucin of the lining epithelium were investigated. RESULTS: MCNs were divided into two groups: (i) a rich (r)-MCN group (n=6), in which more than half of the epithelium was lined by abundant mucinous epithelium; and (ii) a poor (p)-MCN group (n=9), which consisted of the remaining cases. Three patients in the r-MCN group showed invasive carcinoma or high-grade dysplasia, whereas all patients in the p-MCN group showed low-grade dysplasia. Mutations of Kirsten rat sarcoma viral oncogene homolog (KRAS) were more frequent in the r-MCN group (83%) (p-MCN; 11%, p<0.05). CONCLUSION: Mucinous MCNs more frequently have KRAS mutations and higher risk of malignant progression.

A case of rectal neuroendocrine carcinoma in a patient with long-standing ulcerative colitis involving alterations of the p16-Rb pathway.

The patient was a 54-year-old male who had been suffering from extensive ulcerative colitis (UC) for 17 years. Colonoscopy revealed an elevated lesion in the affected rectum, and its biopsy demonstrated neuroendocrine carcinoma (NEC). The surgical specimen obtained on laparoscopic high anterior resection showed extensive active inflammatory and dysplastic lesions and three grossly visible multifocal malignant lesions: a polypoid fungating tumor of NEC (type 1, 20 mm in diameter, pT3) that had been preoperatively noticed, a polypoid fungating tumor of adenocarcinoma (type 1, 22 mm, pT2) and a protruded sessile polypoid tumor (0-Is, 5 mm, pTis) of adenocarcinoma. The NEC was adjacently accompanied by dysplasia-carcinoma sequential lesions and showed a diffuse immunohistochemical overexpression of p53 and p16 proteins and the loss of Rb with no abnormal immunohistochemical staining of microsatellite instability markers and no KRAS mutations. Fifteen months later, the patient showed liver metastasis from the NEC component, followed by bone and spinal metastasis; he died 22 months after the initial diagnosis. A rare case of lethal NEC arising from long-standing extensive UC was reported. The NEC appeared to be UC-related, not incidental, and complicated by progression from dysplasia to carcinoma involving alterations of the p16-Rb pathway.

A resected case of two branch duct-type intraductal papillary mucinous neoplasms showing different clinical courses after a two-year follow-up.

The patient was a 60-year-old man without any particular complaints, but he underwent abdominal computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) due to a fatty liver, which revealed two similar cystic lesions regarded as branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN) in the pancreatic body [BD-IPMN (b), 16 mm in size] and tail [BD-IPMN (t), 13 mm in size] without a "high-risk stigmata" or "worrisome features". He subsequently received follow-up by MRCP every 6 months. Two years later, MRCP showed prominent dilation of the main pancreatic duct (MPD) and mural nodule formation within the dilated MPD adjacent to the BD-IPMN (b). Distal pancreatectomy specimens revealed that the BD-IPMN (b) was lined by low-papillary gastric mucinous epithelium with low-to-intermediate-grade dysplasia and involved the MPD, forming a malignant mural nodule showing pancreatobiliary-type IPMN. In contrast, the BD-IPMN (t) was lined by flat, monolayer columnar gastric mucinous epithelium without atypia, which suggested the possibility of a "simple mucinous cyst". A genetic analysis showed KRAS mutation only in BD-IPMN (b). Differences in the histological and genetic findings between two similar BD-IPMNs in the present case may suggest what kinds of examinations should be performed in patients with BD-IPMNs without any worrisome features.

Successful conservative treatment of emphysematous gastritis.

Emphysematous gastritis is an extremely rare disease with an unfavorable prognosis. To date, very few studies have been conducted regarding the intragastric recovery process based on endoscopic findings. We herein report a case of emphysematous gastritis that improved with long-term (five months) conservative treatment in which we were able to observe the intragastric recovery process endoscopically. In cases in which emphysematous gastritis is suspected, it is important to provide prompt diagnostic imaging (including CT) and early appropriate treatment in order to improve the prognosis.

Small intestinal obstruction caused by anisakiasis.

Small intestinal anisakiasis is a rare disease that is very difficult to diagnose, and its initial diagnosis is often surgical. However, it is typically a benign disease that resolves with conservative treatment, and unnecessary surgery can be avoided if it is appropriately diagnosed. This case report is an example of small intestinal obstruction caused by anisakiasis that resolved with conservative treatment. A 63-year-old man admitted to our department with acute abdominal pain. A history of raw fish (sushi) ingestion was recorded. Abdominal CT demonstrated small intestinal dilatation with wall thickening and contrast enhancement. Ascitic fluid was found on the liver surface and in the Douglas pouch. His IgE (RIST) was elevated, and he tested positive for the anti-Anisakis antibodies IgG and IgA. Small intestinal obstruction by anisakiasis was highly suspected and conservative treatment was performed, ileus tube, fasting, and fluid replacement. Symptoms quickly resolved, and he was discharged on the seventh day of admission. Small intestinal anisakiasis is a relatively uncommon disease, the diagnosis of which may be difficult. Because it is a self-limiting disease that usually resolves in 1-2 weeks, a conservative approach is advisable to avoid unnecessary surgery.