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Hyperplastic Polyps (hyperplastic + polyp)
Selected AbstractsDNA methylation patterns in adenomas from FAP, multiple adenoma and sporadic colorectal carcinoma patientsINTERNATIONAL JOURNAL OF CANCER, Issue 4 2006Coral V.A. Wynter Abstract Colorectal adenomas have traditionally been regarded as homogeneous. The aim of our study was to identify molecular features that may differentiate sporadic adenomas from familial adenomas such as Familial Adenomatous Polyposis (FAP) and Multiple Adenoma patients. DNA methylation was tested at Methylated IN Tumor (MINT) loci (1,2,12,31) and the CpG promoter region of genes MLH1, HPP1, MGMT, p14ARF and p16INK4a in FAP-associated adenomas (33) from 5 patients with a known APC mutation (Group 1, FAP), adenomas (29) from 4 Multiple Adenoma patients (Group 2 Multiple), adenomas (14) from 3 patients with sporadic colorectal cancers showing high microsatellite instability (Group 3, MSI-H) and adenomas (16) from 7 patients, with sporadic colorectal cancers showing microsatellite stable or low level instability (Group 4, MSS/MSI-L). Aberrant Crypt Foci (ACFs), Hyperplastic Polyps (HPs) and cancers were also examined for methylation status as well as K- ras mutation. Multiple Adenoma patients were examined for germline polymorphisms in the base excision repair gene, MYH. The familial syndrome, FAP -associated adenomas showed a significantly low frequency of MINT methylation (15.5%,) compared to sporadic MSS/MSI-L-associated adenomas (35.5%). Group 3 (MSI-H) adenomas were different in that many showed serration and a high level of methylation (57.1%). Group 2, Multiple Adenoma cases, resembled sporadic MSS/MSI-L-associated adenomas. However the promoter regions of key genes, MGMT, p14ARF and p16INK4a were methylated to a greater extent than MINTs in both sporadic and familial adenomas. Genetic profiling of adenomas supports the concept that adenomas belonging to familial syndromes pursue a different pathway to tumorigenesis than their sporadic counterpar/ts from their earliest formation. © 2005 Wiley-Liss, Inc. [source] LARGE HYPERPLASTIC POLYP DEVELOPING AFTER ENDOSCOPIC MUCOSAL RESECTION OF GASTRIC ADENOMA IN A PATIENT RECEIVING IMMUNOSUPPRESSIVE THERAPYDIGESTIVE ENDOSCOPY, Issue 2 2006Geum-Youn Gwak A 59-year-old man underwent endoscopic mucosal resection (EMR) for gastric adenoma. He had suffered from end-stage renal disease for several years and had received renal transplantation some 5 months before EMR. Subsequently, he took immunosuppressive agents. Follow-up gastrofiberscopy 6 months after EMR showed a sessile polyp at the resection site twice as large as the original adenoma; biopsy specimens revealed a hyperplastic nature. At the time of writing, this hyperplastic polyp has neither increased in size nor developed adenomatous or carcinomatous changes by histological examinations over the past 5 years. Therefore, this is a case of hyperplastic polyp occurring at the gastric adenoma resection site, and suggests the possible effect of immunosuppressive therapy on the post-EMR healing process and hyperplastic polyp development. [source] OPTICAL/DIGITAL CHROMOENDOSCOPY DURING COLONOSCOPY USING NARROW-BAND IMAGING SYSTEMDIGESTIVE ENDOSCOPY, Issue 2005Yasushi Sano This review is regarding the narrow-band imaging (NBI) system which has been developed at National Cancer Center Hospital East, Japan. The technology of the NBI system is based on modifying the spectral features by narrowing the bandwidth of spectral transmittance using various optical filters. The NBI system consists of three filters, 415,30 nm, 445,30 nm, and 500,30 nm, which are used as observing the fine capillaries in the superficial mucosa is essential to identify gastrointestinal neoplasms. The NBI system has been in development since 1999 and the first report of it's efficacy for gastrointestinal tract use was reported in 2001. In our pilot study, the NBI system may be sufficient to differentiate hyperplastic polyp from adenomatous polyp, and to visualize neoplasia with image processing in real-time during colonoscopy without the need for dye spraying. Herein, we propose the term ,optical/digital chromoendoscopy' using the NBI system and hope that this instrument will become standard endoscopy for in the 21st century. To estimate the feasibility and efficacy of using the NBI system for surveillance or screening examination, randomized control trials should be conducted in the future. [source] Colonic intra-epithelial carcinoma occurring in a hyperplastic polyp via a serrated adenomaPATHOLOGY INTERNATIONAL, Issue 3 2001Masanori Tanaka We present a case of intra-epithelial carcinoma occurring in a serrated adenoma of the colon. The pedunculated polyp, which measured 12 × 10 × 6 mm, was endoscopically removed from the ascending colon of a 78-year-old woman. Histologically, the polyp mainly consisted of serrated adenomatous glands, and had foci of intra-epithelial carcinoma at the top. Hyperplastic (metaplastic) areas were also present in both borders between the serrated adenomatous area and the surrounding normal mucosa. A sequential increase in the degree of dysplasia, and in the number of nuclei positively reactive for Ki-67 and p53 was evident from the hyperplastic areas toward the foci of carcinoma. The polyp described here may represent a carcinogenic potential of hyperplastic polyp via serrated adenoma. [source] Advanced colorectal polyps with the molecular and morphological features of serrated polyps and adenomas: concept of a ,fusion' pathway to colorectal cancerHISTOPATHOLOGY, Issue 2 2006J R Jass Aim :,To establish and explain the pattern of molecular signatures across colorectal polyps. Methods and results :,Thirty-two sessile serrated adenomas (SSA), 10 mixed polyps (MP), 15 traditional serrated adenomas (SA), 49 hyperplastic polyps (HP) and 84 adenomas were assessed for mutation of KRAS and BRAF and aberrant expression of p53. The findings were correlated with loss of expression of O-6-methylguanine DNA methyltransferase (MGMT). KRAS mutation occurred more frequently (26.5%) than BRAF mutation (4.8%) in adenomas (P < 0.001) and particularly in adenomas with villous architecture (50%). Loss of expression of MGMT correlated with KRAS mutation in small tubular adenomas (P < 0.04). BRAF mutation was frequent in HPs (67%) and SSAs (81%), while KRAS mutation was infrequent (4% and 3%, respectively). Of MPs and SAs, 72% had either BRAF or KRAS mutation. Aberrant expression of p53 was uncommon overall, but occurred more frequently in MPs and SAs (12%) than adenomas (1%) (P < 0.04) and there was concordant loss of expression of MGMT. Conclusions :,Molecular alterations that are characteristic of the serrated pathway and adenoma,carcinoma sequence can co-occur in a minority of advanced colorectal polyps that then show morphological features of both pathways. These lesions account for only 2% of colorectal polyps, but may be relatively aggressive. [source] Distinct CpG island methylation profiles and BRAF mutation status in serrated and adenomatous colorectal polypsINTERNATIONAL JOURNAL OF CANCER, Issue 11 2008Yong Ho Kim Abstract A subset of colorectal cancers with CpG island methylator phenotype-high (CIMP-H) is frequently associated with MSI and BRAF V600E mutation. Since limited data are available on different histological types of colorectal polyps, we compared the pattern and the frequency of promoter methylation, CIMP-H, MSI, KRAS and BRAF V600E mutations and the relationship among these molecular parameters and the clinicopathologic characteristics in 110 serrated polyps (48 hyperplastic polyps, 32 sessile serrated adenomas and 30 serrated adenomas) and 32 tubular adenomas using 7 commonly used tumor-associated gene loci. No significant difference in the frequency of overall methylation frequency (86% vs. 100%) and CIMP-H (39% vs. 28%) between serrated polyps and tubular adenomas was observed, but proximally located serrated polyps showed more frequent methylation at 5 of 7 loci examined, and were more likely to be CIMP-H (62% vs. 22%). MGMT methylation was more common in tubular adenomas while MLH1 and HIC1 were more frequently methylated in serrated polyps. BRAF mutation was frequently present in all types of serrated polyps (80%), but was absent in tubular adenomas and was not associated with CIMP or MSI status. These results show comparable frequencies of promoter methylation of tumor-associated genes and CIMP-H, but distinct differences in gene-specific or colonic site-specific methylation profiles occur in serrated polyps and tubular adenomas. BRAF mutation occurs independently of CIMP and MSI in all types of serrated polyps and may serve as a marker of serrated pathway of colorectal carcinogenesis. © 2008 Wiley-Liss, Inc. [source] Long-term use of proton pump inhibitors does not affect the frequency, growth, or histologic characteristics of colon adenomasALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 7 2007M. SINGH Summary Background, The clinical significance of the trophic effects of long-term proton pump inhibitors (PPI)-related hypergastrinemia on colon polyps remains unknown. Aim, To study the frequency, growth, and histology of colon polyps in patients on chronic PPI therapy (cases), compared to those not receiving acid suppression (controls). Methods, Medical records of 2868 consecutive patients who underwent two or more colonoscopies, performed 3 or more months apart were reviewed. Cases (116) that used PPIs between the two colonoscopies were then compared to controls (194). Results, Demographics and risk factors for colon cancer were comparable between the two groups. At baseline the mean frequency and size of adenomatous polyps were similar in cases and controls (P > 0.05) and at follow-up, these were 0.89 and 1.18 (P > 0.05; 95% CI of ,0.08 to 0.66) and 4.09 mm and 4.00 mm (P > 0.05; 95% CI ,2.29 to 2.11), respectively with no significant change. However, control group had a higher mean frequency and size of hyperplastic polyps at baseline as well as at follow-up colonoscopy (P < 0.05). Conclusions, The long-term use of PPI does not influence the frequency, growth, or histology of adenomatous polyps, but is associated with a reduction in both baseline and interval development of hyperplastic polyps. [source] Occurrence and risk factors for benign epithelial gastric polyps in atrophic body gastritis on diagnosis and follow-upALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2005E. Di Giulio Summary Background :,Benign epithelial gastric polyps have been reported to be more common in atrophic body gastritis. The role of Helicobacter pylori infection in the induction of gastric atrophy is well-known. The development of hyperplastic polyps may be in relation to H. pylori infection. Aim :,To investigate occurrence of benign epithelial gastric polyps in atrophic body gastritis patients at diagnosis and follow-up, and the role of H. pylori and other risk factors for the development of benign epithelial gastric polyps. Methods :,A total of 259 consecutive atrophic body gastritis patients included in a follow-up programme, of whom 202 were followed up for median period of 4 years (range: 2,11). At baseline and follow-up gastroscopies, the presence of benign epithelial gastric polyps was evaluated. Biopsies for histology were obtained from all detected benign epithelial gastric polyps. Results :,Frequency of benign epithelial gastric polyps in atrophic body gastritis patients were 4.6% at baseline and 5.9% at follow-up. About 91.7% were hyperplastic polyps. H. pylori infection was detected in 79.2% atrophic body gastritis patients with benign epithelial gastric polyps, and in 70.8% without benign epithelial gastric polyps. Smoking was more frequent among patients with benign epithelial gastric polyps [42% vs. 20%, OR 2.8 (95% CI: 1.2,6.9)]. Conclusions :,Benign epithelial gastric polyps occur in about 5% of atrophic body gastritis patients, and the vast majority are hyperplastic polyps. Smoking habit, but not H. pylori infection, increases the risk for benign epithelial gastric polyps in atrophic body gastritis patients. [source] Small bowel tumours: a 10 year experience in four sydney teaching hospitalsANZ JOURNAL OF SURGERY, Issue 9 2004David S. Rangiah Background: Small bowel tumours are uncommon and can have a long delay prior to diagnosis. The present study aims to compare the use of computed tomography (CT) and contrast small bowel series (SBS) in their diagnosis and to outline the clinical features of small bowel tumours. Methods: A retrospective, case note study was conducted between 1990 and 2000 in four Sydney teaching hospitals. The data collected included clinical features, investigations and tumour characteristics. Results: One hundred and sixty-six people with small bowel tumours were identified (91 malignant; 75 benign). Malignant tumours consisted of adenocarcinomas (31%), carcinoid tumours (12%), lymphomas (7%) and leiomyosarcomas (5%). Benign tumours consisted of adenomas (22%), hamartomas (13%), leiomyomas (4%), inflammatory polyps (4%) and hyperplastic polyps (2%) and a benign schwannoma (1%). Adenocarcinomas were mainly located in the duodenum (P < 0.001) and carcinoid tumours in the ileum (P < 0.001). Malignant tumours were associated with a higher proportion of symptoms (P < 0.01), signs (P < 0.001) and episodes of small bowel obstruction (P < 0.01). Abdominal CT scans demonstrated a greater sensitivity (87.7%) than SBS (72.9%) with a slightly improved sensitivity when both investigations were used (89.3%). Abdominal ultrasound had a lower sensitivity than both of the above investigations of 65%. Gastroduodenoscopy had a sensitivity of 90% for diagnosing duodenal tumours. Operative procedures were performed on 92 patients with a preoperative diagnosis made in 77%. Metastatic spread of malignant tumours was evident in 46%. The sites of spread were to lymph nodes (23%), liver (21%) and distant locations (2%) at diagnosis. Conclusions: Malignant small bowel tumours are more likely to produce symptoms and signs than benign tumours, particularly caused by small bowel obstruction. Abdominal CT is the best radiological investigation for small bowel tumours and has a slight complimentary effect with SBS in improving the chances of detection. Gastroduodenoscopy remains the best investigation of duodenal tumours. [source] Genetic and epigenetic changes in aberrant crypt foci and serrated polypsCANCER SCIENCE, Issue 6 2008Yutaka Suehiro Aberrant crypt foci (ACF) in colorectal mucosa are the earliest known morphological precursors to colorectal cancer and can be subclassified as dysplastic, heteroplastic (non-dysplastic), and mixed types. Serrated adenoma (SA) is a polyp with serrated architecture and dysplasia, and can be subclassified as traditional SA or sessile SA. Sessile SA is thought to be preneoplastic and differs from most lesions in the traditional SA category because of their flat morphology and general lack of cytological dysplasia. Serrated polyps include hyperplastic polyps (HP), SA, and admixed hyperplastic-adenomatous polyps and are considered a morphological continuum encompassing heteroplastic ACF, HP, admixed hyperplastic-adenomatous polyps, and SA. Recent studies have uncovered other developmental pathways including a heteroplastic ACF-HP/SA-carcinoma sequence and a heteroplastic ACF,adenoma,carcinoma sequence. Heteroplastic ACF histopathologically resemble HP and SA. Sporadic HP are usually present in the left colon, are small, and are considered benign. However, adenocarcinoma arising in the setting of colorectal HP or SA, especially in patients with hyperplastic polyposis, has been described. The relationship between heteroplastic ACF, HP, and colorectal cancer is less certain than that of dysplastic ACF. Here, we discuss the current understanding of genetic and epigenetic alterations in the development of colorectal cancer. Our goal is to provide a conceptual framework for understanding the heteroplastic ACF,HP/SA,carcinoma sequence. (Cancer Sci 2008; 99: 1071,1076) [source] Comparison of standard vs high-definition, wide-angle colonoscopy for polyp detection: a randomized controlled trialCOLORECTAL DISEASE, Issue 10Online 2010G. Tribonias Abstract Aim, We sought to compare the performance of colonoscopy using a high-definition, wide-angle endoscope vs a standard colonoscope for the detection of polyps. Method, A total of 390 patients were prospectively randomized into high-definition colonoscopy group (HD, n = 193) and standard colonoscopy group (SC, n = 197). Results, Analysis demonstrated that there were significant differences between the two groups, as far as the overall rate of polyps (SC, 1.31 ± 1.90; HD, 1.76 ± 2.31; P = 0.03) and the rate of small hyperplastic polyps (size < 5 mm; SC, 0.10 ± 0.36; HD, 0.25 ± 0.61; P = 0.003) were concerned. No significant differences between the two groups were observed, regarding large polyps (size , 10 mm; SC, 0.39 ± 0.89; HD, 0.48 ± 0.80; P = 0.10), medium polyps (10 mm > size , 5 mm; SC, 0.60 ± 1.46; HD, 0.58 ± 1.25; P = 0.31) and small polyps (size < 5 mm; SC, 0.32 ± 0.86; HD, 0.71 ± 1.65; P = 0.09). Similarly, no significant differences were demonstrated in the detection rate of adenomas and hyperplastic polyps, large adenomas, medium adenomas, small adenomas and large and medium hyperplastic polyps. Conclusion, High-definition colonoscopy led to a significant increase in the polyp detection. [source] The impact of new screening protocol on individuals at increased risk of colorectal cancerCOLORECTAL DISEASE, Issue 7 2007T. Mak Abstract Objective, Screening colonoscopy has been shown to reduce mortality and cancer stage in hereditary nonpolyposis colorectal cancer (HNPCC) individuals. However, the benefit of screening in intermediate risk groups is unknown. The most recent national guidelines have recommended a reduction of screening frequency for the intermediate risk group. Therefore, this study aims to compare the results of colonoscopic screening in HNPCC and intermediate risk groups and assess the effect of the most recent screening protocol recommendations. Method, A total of 244 individuals; 108 from HNPCC families (28 mismatch repair gene carriers) and 136 from intermediate risk families were referred for regular colonoscopic screening by the Regional Genetics Service. Findings from 417 colonoscopies performed between 1992 and 2003 were evaluated. Results, A total of three cancers, 39 adenomas and 41 hyperplastic polyps were found in the HNPCC group compared with one cancer, 22 adenomas and 19 hyperplasic polyps in the intermediate risk group. If the recent screening guidelines for the intermediate group were applied, then 89 (44%) fewer colonoscopies would have been performed. Although no cancers would have been missed, six adenomas (mean size = 5.7 mm, range 2,10 mm) with two graded as severely dysplasic and six hyperplastic polyps would not have been detected. Conclusion, The detection rate and distribution of adenomas were similar in both groups. If the new colonoscopic screening recommendations for the intermediate risk group had been applied, a small number of significant lesions would have been missed. [source] | ||||||||||||||||||||||