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Background and study aims: The clinical benefit of endoscopic submucosal dissection (ESD) for superficial duodenal neoplasias has not yet been verified. The aims of this study were to validate the feasibility and long-term outcomes of ESD for nonampullary superficial duodenal neoplasias, larger than 20 mm. Patients and methods: 41 patients, with 41 nonampullary large superficial duodenal neoplasias, who underwent ESD between April 2005 to March 2013 were included in the study. The short- and long-term outcomes were retrospectively evaluated, related to tumor size, resection size, histological type, invasion depth, complete resection rate, operation time, perforation rate, delayed bleeding rate, local recurrence rate, distant metastasis, and survival rate. Results: ESD was successfully completed in 38 of 41 patients (92.7 %). The median sizes of tumors and resected specimens were, respectively, 26 mm (range 20 – 70 mm) and 36.5 mm (range 23 – 80 mm). Histopathological findings showed 13 adenocarcinomas (12 mucosal, 1 submucosal) and 28 adenomas (26 high grade dysplasia, 2 low grade dysplasia). The complete resection rate was 89.5 % (34 /38 tumors). The mean operation time was 128.3minutes. Perforation during ESD occurred in 39 % and delayed bleeding occurred in 18.4 %. The median observation period was 48 months (range 3.2 – 94.1 months), and no local recurrence or distant metastasis was seen during this time, representing a disease-free survival rate of 100 %. Conclusions: ESD for nonampullary large superficial duodenal adenocarcinoma/adenoma is feasible with favorable long-term outcomes. However, because of the high complication rate due to its technical difficulty, experience and skill of the operator, along with adequate perioperative management, are essential.

Background: Although cases of reflux esophagitis (RE) developing after treatment to eradicate Helicobacter pylori have been discussed in some detail, no reports are available concerning the histologic examination of RE both before and after eradication therapy. Materials and methods: Sixty-one patients and 111 specimens were investigated using endoscopic and histologic techniques. The histologic findings including basal zone height, papillar height, Ki-67 labeling index, and COX-2 expression before and after treatment for H. pylori infection were compared with those in normal controls and patients with endoscopic RE. Results: Twelve months after eradication therapy, the incidence of newly developed endoscopic RE was 20% (5/25). Basal zone height and papillar height had increased at 1 month, but had returned to pretreatment levels after 12 months of eradication therapy. The Ki-67 labeling index was significantly increased 1 and 12 months after eradication therapy compared to values before treatment. COX-2 expression gradually increased after the treatment. The phenomena linked to esophagitis appeared after eradication therapy. However, the severity and extent of these signs were not so high after the treatment of H. pylori than those in patients with overt reflux esophagitis. Focusing on the patients with hiatal hernia, papillar height and Ki-67 labeling index increased significantly after eradication therapy, values being almost the same as those in the patients with endoscopic RE. Conclusions: Hiatal hernia plays an important role in the possible occurrence of hidden RE after treatment for a H. pylori infection.

Background. The ideal second-line treatment regimens for Helicobacter pylori infection may differ between the areas, countries and races. Aim. The aim was to confirm which was the better regimen for second-line therapy after treatment failure with a standard triple therapy in Japan, a high dosage of levofloxacin- or metronidazole-based therapy. Patients. Sixty outpatients with persistent H. pylori infection after a standard triple therapy were enrolled in this prospective, open-label and randomised trial. Methods. The subjects were randomly administered levofloxacin (300 mg b.d.)- or metronidazole (500 mg b.d.)-based therapy with lansoprazole (30 mg b.d.) and amoxicillin (1000 mg b.d.) for 7 days, and the cure rates and side effects were analysed. Antimicrobial susceptibility was also examined before second-line therapy using the E-test. Results. Good compliance was obtained without severe side effects in both the groups except for two patients. The cure rates, expressed as intention-to-treat and per-protocol analyses, respectively, were 70.0 and 72.4% in the levofloxacin group, and 96.7 and 100% in the metronidazole group. Each regimen often overcame even clarithromycin-resistant strains. Conclusion. Metronidazole-based triple therapy is recommended as second-line therapy in Japan, and levofloxacin-based therapy can be an alternative treatment option.

Background and study aim: Endocytoscopy (ECS) enables in vivo microscopic imaging, which allows analysis of mucosal structures at the cellular level; however, limited data are available on the validity of ECS in the stomach. The aim of this study was to evaluate the feasibility of ECS in the diagnosis of early gastric cancer. Patients and methods: Gastric lesions that were the targets of histopathological diagnosis by endoscopic submucosal dissection or biopsy specimen were prospectively enrolled and evaluated using a single charge-coupled device-integrated endocytoscope, following double staining with crystal violet and methylene blue. High grade ECS atypia was defined according to specific irregularities in gland structure and cell nuclei. The primary end point was the accuracy of ECS diagnosis for gastric cancer, using histopathological diagnosis as the gold standard. Results: A total of 82 lesions were investigated, including 23 early gastric cancers, 10 gastric adenomas, and 49 non-neoplastic lesions. Ten lesions could not be clearly observed by ECS because of poor staining due to viscous mucus or plaque; thus, assessability rates with ECS were 88 % in total and 91 % for gastric cancer. High grade ECS atypia was observed in 86 % of assessable gastric cancers, but not in any cases of gastric adenomas or non-neoplastic lesions. The sensitivity, specificity, positive and negative predictive values of high grade ECS atypia as the criterion for the diagnosis of gastric cancer were 86 %, 100 %, 100 %, and 94 %, respectively. No serious complications occurred during or after the examinations. Conclusion: ECS is a clinically feasible modality to obtain in vivo histology, with high diagnostic accuracy in gastric cancer.

Acute graft-versus-host disease (GVHD) occurring within 100 days post-transplant is one of critical factors influencing prognosis in transplant recipients. Among cases of GVHD of the gastrointestinal (GI) tract, GVHD rarely affects the upper GI. In this study, we retrospectively examined the frequency of upper GI GVHD and diagnostic accuracy.From among 868 patients who underwent allogeneic hematopoietic stem cell transplantation at our hospital between January 2005 and June 2012, 115 of whom underwent biopsy for upper GI symptoms. The endoscopic findings and histologic diagnosis from these 115 patients were retrospectively analyzed.GVHD was histologically diagnosed in 85 patients overall (9.8% of all 868 transplant recipients). Although gastric mucosal exfoliation was not commonly observed, this endoscopic finding when used as a diagnostic predictor had both a specificity and positive predictive value (PPV) of 100%. When using redness, luster, and mucosal change as predictors, specificity and PPV were relatively high, suggesting that these gastric endoscopic findings are useful in the diagnosis of upper GI GVHD. Among the duodenal endoscopic findings, erosion as a diagnostic predictor had both a high specificity and PPV. The biopsy results often lead to a diagnosis of GVHD even in cases judged to be endoscopically normal.Among the gastric endoscopic findings, mucosal exfoliation, although rare, and redness, luster, and mucosal change are likely to be useful diagnostic predictors of upper GI GVHD. GVHD was frequently diagnosed in patients with endoscopically normal duodenum, suggesting that biopsies are important for definitive diagnosis.

Endoscopic submucosal dissection (ESD) is a widely accepted technique for the management of gastric tumors. However, residual or recurrent tumors can occur after ESD; currently, there is no adequate management strategy for these tumors. Thus, the aim of the present study was to establish a strategy of secondary ESD (sESD) for cases with positive lateral margins (LM+), which cause post-ESD residual or recurrent tumors.Fifty-three lesions that were subjected to ESD were diagnosed as LM+ with suspected local residual tumor. The short- and long-term outcomes of early sESD (performed shortly after the initial ESD in LM+ cases to prevent local recurrence) were retrospectively compared with those of late sESD (performed after the detection of recurrent tumors).Of the 53 LM+ cases, the local residual positive rate was 38.5 % (10/26) in those undergoing early sESD or additional surgery and the local recurrence rate was 29.6 % (8/27) in those that were not treated. Thus, the overall incidence of residual or recurrent tumors in LM+ cases was 34.0 % (18/53). Both early and late sESD had favorable outcomes with no severe complications: 100 % of early sESD resections were curative, compared with 86.7 % of late sESD resections, over the course of a mean (±SD) observation period of 50.8 ± 16.7 months. The performance of early sESD was significantly greater than that of late sESD (in terms of dissection speed).Early sESD is more reliable than late sESD as a therapeutic strategy for salvaging residual tumors and for preventing recurrence. However, if a tumor has already recurred, late sESD remains useful.

Esophageal achalasia is often associated with esophageal cancer. However, in many cases, esophageal cancer tends to be found in an advanced stage, with a poor prognosis. However, early-stage cancer was detected recently due to the advances in endoscopic instruments. In those cases, it is important to facilitate successful treatment by endoscopic submucosal dissection. We analyzed a total of six cases of esophageal cancer with achalasia in four patients treated with endoscopic submucosal dissection. Three features common to all six cases had a bearing on how endoscopic submucosal dissection was performed. First, esophageal dilatation and diminished peristalsis facilitated the performance of successful endoscopic submucosal dissection. Second, the esophageal wall was thickened, primarily with muscular tissue. Third, the submucosal layer contained abundant blood vessels that made it difficult to minimize bleeding during dissection. Those findings suggest that endoscopic submucosal dissection for early esophageal cancer associated with achalasia is a safe and potentially curative procedure. It is important, therefore, to detect esophageal cancer early.

Magnifying endoscopy with narrow band imaging (ME-NBI) is useful to diagnose invasion depth of superficial esophageal cancer. The purpose of this study was to evaluate the utility of ME-NBI of superficial pharyngeal cancer.Between April 2008 and June 2012, 146 lesions in 104 patients who underwent ME-NBI and en bloc resection were retrospectively analyzed. Based on magnifying endoscopic classification, proposed by the Japan Esophageal Society, microvasculature type was classified into B1, B2, and B3.B1 alone, B2, and B3 were observed in 128, 14, and 4 lesions, respectively. The frequency of subepithelial cancer were 20.3% (26 of 128), 78.6% (11 of 14), and 100% (4 of 4), respectively (p.05). Mean invasion distance were 650 μm, 720.0 μm, and 2256.5 μm. Positive and negative predictive value for diagnosing subepithelial cancer based on the presence of B2 or B3 was 83.3% (15 of 18) and 79.7% (102 of 128).ME-NBI is useful to determining invasion depth of superficial pharyngeal cancer.

Recently, the use of endoscopic submucosal dissection (ESD) for gastric submucosal tumor (gSMT) and the development of laparoscopic and endoscopic cooperative surgery (LECS) have enabled either preservation of the stomach or minimization of the extent of partial resection. In the present study, the outcomes following the recent introduction of LECS for gSMT are presented. The aim of this retrospective study was to evaluate the feasibility and safety of LECS for gSMT, including esophagogastric junction (EGJ) SMT.LECS is indicated for lesions that have an intragastric growth pattern, or for which fundusectomy can be avoided despite an extragastric growth pattern. We retrospectively evaluated the outcome of LECS carried out in 25 patients including five EGJ SMT.Surgery was completed achieving an R0 resection rate of 100% with no postoperative complications. Mean tumor size was 32.3 ± 13.5 mm and mean resected specimen size was 37.6 ± 13.5 mm. Resection margins were tumor-free in all cases, with adequate minimum surgical margins, and precise conclusive diagnosis was achieved with perfect operative specimens. Endoscopic confirmation of the EGJ enabled the extent of resection to be minimized and the stomach to be preserved, avoiding fundusectomy. Although there were significant differences in tumor size and resected specimen size between EGJ SMT and non-EGJ SMT, there were no significant differences in outcomes of the LECS procedure.LECS is feasible and safe for cases with gSMT including lesions adjacent to the EGJ.

A 59-year-old woman had been admitted to our hospital every two months for over a past year because of severe right abdominal pain. Colonoscopy revealed dark blue mucosa extending from the cecum to the transverse colon, and abdominal computed tomography showed wall thickening and linear calcification along the wall from the cecum to the transverse colon. Based on these findings, the patient was given a diagnosis of idiopathic mesenteric phlebosclerosis. Subsequently, we found that she had been a long-term user of a Chinese herbal product containing Gardeniae fructus for allergic rhinitis. After discontinuing the product, the patient has been free of abdominal pain for a year.

A 75-year-old man was admitted because of watery diarrhea, hematochezia and right lower abdominal pain. Many deep undermining colonic ulcers were found by colonoscopy, and we detected trophozoite amoeba pathologically. Metronidazole was administered orally from 3 days after admission. However, since CT demonstrated a huge abscess in the abdominal cavity, we performed percutaneous drainage from 17 days after admission. On day 157, the patient was discharged, because the colonic ulcers had almost healed, and trophozoite amoebas were not recognized pathologically.

Backgrounds. Magnifying endoscopy with narrow-band imaging (ME-NBI) has become essential for determining tumor margin in early gastric cancer (EGC). Here, we investigated the usefulness of ME-NBI for assessment of invasion depth in EGC. Methods. For 119 patients who had undergone ME-NBI and en bloc resection by endoscopic submucosal dissection, three physicians prospectively examined high-magnification ME-NBI images for clinical features such as presence or absence of dilated vessels (D vessels). Cases with D vessels verified by at least two physicians were assigned to group V, and others were assigned to group N. We then compared clinicopathological factors associated with the groups. Results. Groups V and N consisted of 18 and 101 patients, respectively. There were no significant differences in age, gender, tumor size, tumor location, gross morphology, or histological type. The percentage of submucosal cancer was 9.9% (10/101) in group N and significantly higher at 33.3% (6/18) in group V (). When the presence of D vessels was considered a diagnostic criterion for submucosal cancer, diagnostic accuracy, sensitivity, and specificity were 81.5, 37.5, and 88.3%, respectively. Conclusions. The results suggest that identification of D vessels using ME-NBI can assist in the assessment of invasion depth in EGC.

Residual or locally recurrent lesions may occur after endoscopic therapy for epithelial colorectal tumors. Additional endoscopic mucosal resection is difficult for large lesions. Endoscopic submucosal dissection may be useful for such lesions, but may be more technically difficult for residual/locally recurrent lesions than for primary lesions. This study evaluated the efficacy of endoscopic submucosal dissection for residual/locally recurrent lesions in comparison with primary lesions.This retrospective case-control investigated 34 residual/locally recurrent lesions and 384 primary lesions treated using endoscopic submucosal dissection. Tumor size, resected specimen size, procedure duration, en bloc resection rate, curative resection rate, histology, associated complications, and recurrence rate were compared between groups.Procedure duration tended to be longer (85 ± 53 min vs 73 ± 55 min) and tumors were significantly smaller (20 ± 13 mm vs 33 ± 20 mm; P0.001) in the residual/locally recurrent group, compared with primary lesions. Both groups showed similar percentages of en bloc (100% vs 97.4%) and curative resection (88.4% vs. 83.6%). Perforation rate was significantly higher in the residual/locally recurrent group (14.7% vs 4.4%, P0.05). However, emergency surgery was only needed in 1 of 5 cases in the residual/locally recurrent group, with the remaining 4 cases conservatively managed using endoclips.Endoscopic submucosal dissection for residual/locally recurrent lesions was curative and efficacy. This procedure could help to avoid surgical resection and frequent follow-up examinations in many patients.

The patient was a 70-year-old male with superficial hypopharyngeal cancer and advanced cancers of the esophagus and stomach. In his past history, a cardiac pacemaker was implanted for sick sinus syndrome. Further examination showed esophageal cancer had metastasized to the cervical lymph nodes and invaded the trachea. There was no surgical indication. In terms of chemoradiotherapy, it was thought to be possible because the patient was not pacemaker- dependent and radiotherapy could be planned in such a way as to keep the dose to the pacemaker as low as possible. Electrocardiogram was monitored during the treatment. In addition to the usual observation, the patient's cardiac symptoms and pacemaker status were assessed before and soon after the completion of radiotherapy. S-1 was selected as a concomitant chemotherapy. In liaising with the cardiologist and radiologist, chemoradiotherapy was achieved without pacemaker malfunction, and shrinking of tumors was also detected.

Tu1714 Gastric Cancer: Are WE Missing the Opportunity of Early Diagnosis? Ramiro Tapia-Sosa*, Luis Uscanga Gastroenterology, Instituto de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico Background/Aims: Gastric Cancer (GC) is the third-leading cause of death from Cancer in Mexico. Based on the diagnosis and treatment guidelines of this country, the upper gastrointestinal endoscopy (UGE) with biopsy is the most efficient procedure to identify this disease. We aim to know the number of patients, and their clinical features, who have had at least one UGE before the definitive diagnosis of GC. Methods: All the patient medical files with GC who were admitted to a health Institute in Mexico City in a period of 5 years were reviewed. The total subjects were divided into: Group A, those with only one UGE performed to establish the GC diagnosis, and Group B, those patients who had more than one procedure before the identification of GC within a maximum period of 24 months. Results: One hundred and twelve patients with GC were diagnosed with GC. Group A was 70% (78/112) of the total population under study and Group B consisted of the remaining 30% (34/112). The time between the onset of symptoms and the diagnosis of this disease was statistically significantly (p!0.05) greater in the latter group (Table 1). Twenty-six of the 34 patients of Group B had an endoscopic view consistent with neoplasm; however, they were not histologically confirmed. The remaining eight were not suspected of neoplasm neither endoscopically nor microscopically. An important number of patients (11%) of the study group had a delayed diagnosis due to a time between studies greater than 6 months. The variable that implied a risk for delayed diagnosis of GC was the use of proton pump inhibitors (HR 3.2, CI 95% 1.4 7.2) which also has an effect on prognosis (Table 2). Conclusions: The majority of patients with a previous UGE had a macroscopic image that suggested GC which forces the physician to recheck the tissue under microscope or, if it were the case, repeat the study. Table 1. Univariate analysis: Group A vs B

Mucinous adenocarcinoma (MC) is a unique pathological type of colorectal cancer (CRC). The development of MC is often associated with intestinal inflammation and/or microsatellite instability (MSI). Moreover, MC has clinicopathological characteristics that render making the correct diagnosis difficult such as extramural progression. Meanwhile, intestinal spirochetosis (IS) is a condition in which colonic epithelial cells are colonized and/or infected by spirochetes. Intestinal inflammation due to IS occurs by the destruction of colonic microvilli and induces chronic diarrhea. Recently, it was reported that the prevalence of IS tended to be high in patients with sessile serrated adenomas/polyps, the precursor of MSI-high CRC including MC. This study presents a case of MC in the setting of intestinal inflammation due to IS and tries to clarify the cause of MC development by performing immunohistochemical stain of resected specimen for DNA mismatch repair (MMR) proteins. This patient is a 63-year-old man with no symptoms who had a positive fecal occult blood test. Subsequent endoscopic findings and biopsy results revealed intestinal stricture of the transverse colon and chronic infective colitis associated with IS. Metronidazole therapy was initiated but was not effective. Although follow-up colonoscopy was performed repeatedly, intestinal perforation occurred 20 months later. Subtotal colectomy and ileostomy were performed. Pathological examination of resected specimens revealed MC with normal expression of MMR proteins, including MLH1, MSH2, MSH6, and PMS2. The histopathological classification was Union for International Cancer Control (UICC) IIIB and adjuvant chemotherapy was initiated. This is an interesting case of MC developing in the setting of chronic colitis associated with IS. It seemed that the cause of MC development was not MSI but intestinal inflammation. Besides, endoscopic diagnosis of MC in this case was difficult because of the extramural progression and lack of obvious atypical colonic glands in biopsy specimens. This report provides evidence for an association between neoplasm and IS-induced intestinal inflammation. Moreover, we suggest that making the diagnosis of MC could be difficult because of its unique clinicopathological characteristics.

Background: Recent years have witnessed a decrease in the rate of Helicobacter pylori eradication due to antimicrobial resistance, clarithromycin or metronidazole resistance in particular. As one of the alternatives to the standard regimens, levofloxacin-containing therapy has been considered a promising regimen. Nevertheless, there is a little information concerning the prevalence of levofloxacin resistance and this resistance mechanism. Materials and Methods: Levofloxacin susceptibility was examined using E-test in 507 H. pylori strains clinically isolated in Japan from 2001 to 2004. Mutation patterns in the quinolone resistance-determining regions of the gyrA and gyrB genes were evaluated, performing direct sequencing of 68 levofloxacin-resistant and 50 susceptible strains. Results: Primary levofloxacin resistance was found in 76 (15.0%) strains. Fifty-seven (83.8%) of 68 levofloxacin-resistant strains analyzed had point mutations in gyrA at Asn-87 or Asp-91, while seven (14.0%) of 50 susceptible strains had gyrA mutations. There was a significant difference in the occurrence of gyrA mutations between levofloxacin-resistant and -susceptible strains (p

TGF-beta1 is a well-known immunosuppressive cytokine that inhibits inducible nitric oxide synthase (iNOS) gene expression in various cells including macrophages. In this study, we investigated the suppressive mechanisms of TGF-beta1 on IFN-gamma-induced iNOS gene expression using the murine macrophage-like cell line RAW 264.7. TGF-beta1 decreased iNOS protein amount through enhanced degradation, although TGF-beta1 did not affect IFN-gamma-induced iNOS mRNA level or stability. In addition, the enhancement of iNOS protein degradation by TGF-beta1 treatment was almost completely blocked by MG132, a proteasome inhibitor. Furthermore, TGF-beta1 enhanced the trypsin-like activity of proteasomes in the presence of IFN-gamma, although did not enhance the peptidylglutamyl-peptide hydrolyzing and chymotrypsin-like activities of proteasomes. The level of ubiquitinated iNOS protein was not significantly altered by IFN-gamma or IFN-gamma plus TGF-beta1 treatment. Because MG132 inhibited iNOS protein degradation and IFN-gamma plus TGF-beta1 treatment increased the trypsin-like activity of proteasomes, we hypothesized that TGF-beta1 might enhance iNOS protein degradation via the ubiquitin-proteasome pathway in the presence of IFN-gamma. We propose that these mechanisms of TGF-beta1 in the posttranslational regulation of iNOS gene expression may contribute to suppression of excess nitric oxide during inflammatory processes.

Platelet-derived growth factor (PDGF) plays an important role in the pathogenic course of atherosclerosis, pulmonary fibrosis, and glomerulonephritis, and increased activity of the PDGF signaling pathway has been implicated as a contributing factor in the progression of the diseases. Taurine may be a prophylactic amino acid for atherosclerosis not only by decreasing plasma cholesterol level, but also by inhibiting the cell proliferation-signaling pathway. To elucidate how taurine affects the signaling pathway, we investigated the effect of taurine on the expression of immediate-early genes and activation of mitogen-activated protein kinases (MAPKs) in NIH/3T3 cells as standard mesenchymal cells. Taurine inhibited PDGF-BB-induced c-fos and c-jun mRNA expressions dose-dependently, although structural analogues of taurine did not. Taurine decreased the PDGF-induced p44/p42 ERK (extracellular signal-regulated kinase) phosphorylation state dose-dependently, although no phosphorylation was observed on JNK/SAPK (c-Jun N-terminal kinase/stress-activated protein kinase) and p38 MAPK. Further, PDGF-BB-induced tyrosine phosphorylation of the PDGF-beta receptor was not influenced by treatment with taurine, indicating that taurine never affects ligand-receptor interaction, and may act downstream of the PDGF receptor. Thus, the inhibitory mechanism of taurine on PDGF-induced c-fos and c-jun mRNA expressions may depend on the p44/p42 ERK pathway, but not on PDGF-beta receptor tyrosine phosphorylation, JNK/SAPK or p38 MAPK pathway. These results suggest that taurine may suppress the cell proliferation-signaling pathway through the inhibition of ERK activity and immediate-early gene expression.

Platelet-derived growth factor-BB (PDGF-BB) is involved in the development of atherosclerosis in conjunction with the migration and the proliferation of vascular smooth muscle cells. PDGF-BB is produced by activated macrophages, smooth muscle cells and endothelial cells, or released from platelets, and its expression is increased in atherosclerotic lesions1,2. Thus, PDGF-BB is thought to play a critical role for the intimai thickening in the lesions of atherosclerosis.

met the WHO criteria for SPS. Only one of these was suspected by the referring physician. Twelve (60%) of them were either diagnosed or suspected by the endoscopist at our center, and 8 were recognized only during the study review. Compared to all other patients without SPS, those with SPS were more likely to have an index lesion (the lesion that led to referral) that was serrated (43% vs 1.5%), to have a proximal colon index lesion (58% vs 26%), and to be current smokers (42% vs 15%). Including the first colonoscopy at our center and 26 total follow-up colonoscopies, the endoscopist at our center removed 183 serrated polyps (hyperplastic polyps and sessile serrated polyps) from the 20 patients, including 68 that were 1cm in size. Four patients were sent for surgical resection of involved colon. There were also 51 conventional adenomas removed from 19 patients. Eighteen of the 20 SPS patients met the WHO criterion of 5 serrated polyps proximal to the sigmoid, of which 2 are 1cm in size. Failure to recognize SPS by the referring physician was at least partly related to unrecognized serrated lesions. Failure to recognize SPS by the endoscopist at our institution was the result of not systematically applying WHO criteria to the polyp findings. Conclusions: SPS was common in a cohort of patients with large sessile colorectal polyps, and frequently unrecognized. These data suggest the need for better detection of serrated lesions, better awareness of SPS and consistent application of SPS criteria to the polyp findings of individual patients.