Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Polyps”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed2004

[Application of metal hemoclip for endoscopic polypectomy in children with thick-pedunculated intestinal polyps].

OBJECTIVE: With the development of endoscopic therapy in children, endoscopic electrocoagulation polypectomy had gradually replaced surgery and became an important method to resect gastrointestinal polyps in children. Simple electrocoagulation polypectomy could often bring some complications of gastrointestinal bleeding and perforation because of incomplete electrocoagulation or mechanical incision, especially in gastrointestinal thick-pedunculated polyps which always have thick nutrient blood vessel. Hemoclips can successfully interdict arteriovenous blood because it can clamp tissue firmly without causing necrosis around the target area. Based on its good mechanical hemostasis, hemoclips are not only widely used in treating bleeding like from ulcer, tumor and variceal ligation but also used in removal of thick-pedunculated gastrointestinal polyps in adults. This paper describes the application of endoscopic electrocoagulation with metal hemoclips to remove thick-pedunculated intestinal polpys in children for the first time, sums up the experience and evaluates its efficacy and safety. METHODS: Between October, 2001 and December, 2002, 5 cases with thick-pedunculated intestinal polpys were presented. The age of the patients ranged from 3 to 5 years. The clinical features were gastrointestinal bleeding or abdominal pain. The longest course of disease was 2 years. Enough preparations for alimentary tract were necessary for polypectomy. The procedures were performed under general anesthesia in order to avoid the risk of bleeding aspiration. Endoscopy was performed in the standard fashion. The apparatus included electronic colonic endoscope (XQ 200, Fuji Corp, Tokyo, Japan), snare (XQ200, Fuji Corp, Tokyo, Japan), impeller of the clip (HX-5QR-1) and hemoclip (MD850) which could be passed through the biopsy channel of endoscope. The clip was completely covered with a hood avoiding any injury to the mucous membrane. The pedicel with diameter of more than 1.0 cm underwent endoscopic electrocoagulation polypectomy with hemoclips. The clip contacted polyps in upright direction. One or more hemoclips were selected to clamp the proximal basement of the pedicel in terms of the pedicel diameter. Turning of the red colour of polyps to purple suggested that hemoclip interdicted arteriovenous blood effectively. The clip was then shut off and electrocoagulation polypectomy was followed. Six polyps were observed and removed. RESULTS: Six polyps including 2 transverse colon polyps and 4 descending colon polyps were resected. Pathological results showed that 3 were juvenile polyps and the other 3 adenomatous polyps. All the polyps were completely resected. The diameter of pedicel were 1.2 - 2.2 cm. The head and pedicel of the biggest polyp was about 5 cm x 5 cm and 2.2 cm, respectively, and five clips were used in order to remove it. No complications of bleeding and perforation were observed in these children. All hemoclips were expelled from intestines within one week. The symptoms of these patients disappeared. CONCLUSION: Mechanical hemostasis with hemoclips successfully interdicted arteriovenous blood of thick-pedunculated polyps. Hemoclips can successfully prevent the complications of bleeding and perforation. The clipping brings about a new method in endoscopic therapy. Endoscopic electrocoagulation polypectomy with hemoclips is a simple, safe and effective method to treat thick-pedunculated gastrointestinal polyps in children and it is a valuable tool in polypectomy for children.

Child↗
PubMed1993

Small rectosigmoid polyps as markers of proximal neoplasms.

PURPOSE: The aim of this study was to determine the spatial distribution and histotype of small colorectal polyps and to determine the validity of distal-small colorectal polyps as markers of proximal neoplasms. METHODS: In 366 patients who underwent total colonoscopy and removal of all polyps, the presence and features of polyps were recorded. The relationship between proximal neoplasms and distal polyps was investigated in 216 of 366 subjects who had no personal or familial history of colorectal neoplasia. RESULTS: Of 366 patients, 96 were free from polyps. A total of 733 small colorectal neoplasms was removed from the remainder: 79.9 percent neoplastic and 20.1 percent hyperplastic, inflammatory, or hamartomatous. High-grade dysplasia was noted in 2.7 percent of the neoplastic polyps. One adenoma containing invasive carcinoma was observed. In the subset of 216 patients, proximal neoplasms were found in 11.4 percent of those with no distal polyps, 33.8 percent of those with distal-small colorectal polyps only (P < 0.01), and 58.8 percent of those with at least one polyp > 5 mm in diameter (P = 0.001). The proximal neoplasm percentage was the same in patients with at least one adenomatous-small polyp and those with only hyperplastic-small polyps. CONCLUSIONS: A distal-small colorectal polyp, whether adenomatous or hyperplastic, may be a proximal neoplasm marker. Total colonoscopy is thus justified in all patients with distal polyps, regardless of their size and histotype.

Adult↗
PubMed2002

Risk factors for hyperplastic and adenomatous polyps: evidence for malignant potential?

Recent studies have suggested that hyperplastic polyps may be benign precursor lesions for a distinct subset of colorectal tumors. We conducted a clinic-based case-control study to evaluate risk factors for hyperplastic polyps. Cases with hyperplastic polyps (n = 219), adenomas (n = 437), and both types of polyps (n = 138), along with colonoscopy-negative controls (n = 708), were identified at a gastroenterology practice in the Minneapolis area during 1991-1994. A self-administered questionnaire was used to collect risk factor information. Risk factors for hyperplastic and adenomatous polyps were generally similar to those for colorectal cancer. Male sex, smoking, and alcohol consumption were associated with increased risk of all polyp groups; nonsteroidal anti-inflammatory drug use, hormone replacement therapy use, and calcium intake were associated with reduced risk. There was no apparent association between increasing age and hyperplastic polyp risk (P = 0.21) in this analysis, although it was a strong risk factor for adenoma (P < 0.001). The odds ratio (OR) for hyperplastic polyps associated with >25 pack-years of smoking was 4.1 [95% confidence interval (CI), 2.2-7.6], whereas the OR for adenoma alone was 1.3 (95% CI, 0.8-2.3). The OR estimate for individuals diagnosed with both polyp types was 4.2 (95% CI, 1.9-9.3). These results suggest, as one possibility, that the consistent association of adenoma and smoking observed in previous studies may be partially attributable to the inclusion of individuals with both adenomas and hyperplastic polyps in the adenoma case group. To the contrary, individuals with both polyp types may be expressing a phenotype distinct from those who have only adenomas and should be considered separately. Further studies are necessary to establish which polyp phenotypes are related to smoking. Overall, the similarity of the risk profiles of colorectal hyperplastic polyps, adenoma, and cancer provides additional support for the growing body of evidence that some hyperplastic polyps may have neoplastic potential.

Adenomatous Polyps↗
PubMedDate not supplied

Polyps with different grades of dysplasia and their distribution in the colorectum.

BACKGROUND/AIMS: To determine the role of adenomatous polyps in the development of colorectal cancers, we examined the relationship between the distribution and polyps with different grades of dysplasia (low, high), or/and cancers in the colorectum. METHODOLOGY: The distribution of 527 polyps with low-grade dysplasia was compared with that of 121 polyps with high-grade dysplasia, and 10 colorectal cancer lesions with adenomatous polyps in 361 patients who underwent total colonoscopy. RESULTS: The distribution rate of polyps at the distal colon and rectum into polyps with high-grade dysplasia significantly increased in comparison to that into polyps with low-grade dysplasia, respectively (p<0.002). The percentage of polyps with high-grade dysplasia measuring >1 cm significantly increased in comparison to that with low-grade dysplasia measuring >1 cm (p<0.00001). In patients with both adenomatous polyps and colorectal cancers, the polyps with high-grade dysplasia at the distal sites of cancerous lesions increased significantly more than at the proximal sites of cancerous lesions (p<0.05). Polyps with high-grade dysplasia have malignant potentials to intermediate between polyps with low-grade dysplasia and colorectal cancers in our study. CONCLUSIONS: The different distributions of different grades thus suggested that polyps with different grades of dysplasia at various colorectal sites were found to have different malignant potentials for cancer development.

Adenomatous Polyps↗
PubMed2005

Angiogenesis in colon hyperplastic polyp.

Despite the significance of tumor angiogenesis and the extensive knowledge on the molecular basis of blood vessel formation in carcinoma of colorectum, no data exist in hyperplastic polyp. This prompted us to examine angiogenesis in hyperplastic polyp. Eleven small hyperplastic polyps, 13 large hyperplastic polyps and their adjacent normal mucosas were included in this study. Angiogenesis was assessed by immunohistochemistry using monoclonal antibody against CD34. Angiogenic factor, thymidine phosphorylase was also examined by immunohistochemistry. Intra-tumoral microvessel density (IMD) in large hyperplastic polyp was significantly higher than that in small hyperplastic polyp (P<0.01) and that in normal mucosa (P<0.01). DAD in small hyperplastic polyp was also significantly higher than that in normal mucosa (P<0.01). Expression of dThdPase was almost observed in stromal cells in normal, small and large hyperplastic polyp. In addition, the proportion of the stromal cells expressing dThdPase in large hyperplastic polyp was significantly higher than that in small hyperplastic polyp and normal tissue (P<0.01, respectively). The proportion of the stromal cells expressing dThdPase in small hyperplastic polyp was significantly higher than that in normal tissue (P<0.01). The present study provides that angiogenesis may have an important role(s) in the development of hyperplastic polyp and dThdPase in stromal cells may support angiogenesis in hyperplastic polyp. Anti-angiogenic therapy might be available for suppression of hyperplastic polyp.

Antigens, CD34↗
PubMed1994

Hydrocolonic ultrasonography in the detection of colonic polyps and tumors.

BACKGROUND: Hydrocolonic ultrasonography--abdominal ultrasonography in conjunction with the retrograde instillation of water into the colon--has been advocated as an alternative to colonoscopy for detecting colorectal polyps and cancer. We conducted a prospective, blinded trial to evaluate the procedure further. METHODS: Fifty-two consecutive patients (50 men and 2 women; average age, 62 years) who were referred for colonoscopy underwent hydrocolonic ultrasonography followed by colonoscopy. The physicians performing colonoscopy were blinded to the ultrasound results. Patients who had a history of colonic polyps or tumors or who had previously undergone flexible sigmoidoscopy or colonoscopy were excluded. RESULTS: Twenty-two patients had normal results on colonoscopy, 26 had polyps, 3 had cancer and polyps, and 1 had cancer alone. Twenty patients had polyps less than 7 mm in diameter, eight had polyps 7 mm or more in diameter, and one had a polyp of unknown size. Hydrocolonic ultrasonography did not detect any cancers and detected only one polyp > or = 7 mm and one polyp < 7 mm in diameter. The overall sensitivity of ultrasonography for identifying any polyp was 6.9 percent, and for identifying a polyp > or = 7 mm, it was 12.5 percent. Ultrasonography suggested the presence of five masses and five polyps that were not confirmed by colonoscopy. Six patients had incomplete ultrasound studies because of discomfort or the inability to retain water. There were two complications: one patient had two vasovagal episodes, and another had diaphoresis. CONCLUSIONS: Hydrocolonic ultrasonography was less useful than colonoscopy for detecting colorectal polyps and cancers. The usefulness of the technique in screening for colonic polyps and tumors appears to be limited.

Colonic Neoplasms↗
PubMed2002

High-resolution chromoendoscopy for classifying colonic polyps: a multicenter study.

BACKGROUND: Chromoendoscopy may reliably separate adenomatous from nonadenomatous polyps. The aim of this multicenter trial was to determine the accuracy of high-resolution chromoendoscopy for the determination of colonic polyp histology. METHODS: This multicenter trial included 4 academic centers and a primary care practice. In 299 patients referred for routine colonoscopy or sigmoidoscopy, 520 polyps 10 mm in size were sprayed with indigo carmine dye. Using a high-resolution endoscope, the endoscopist predicted the histology of each polyp based on its surface characteristics. Hyperplastic polyps had a "pitted" surface pattern of orderly arranged "dots" that resembled surrounding normal mucosa. Adenomatous polyps had at least one surface "groove" or "sulcus." Each polyp was subsequently resected for histopathologic evaluation. RESULTS: The resected polyps were comprised by 193 adenomas (37%), 225 hyperplastic polyps (43%), and 102 "other" types (20%). Forty polyps (7.7%) could not be classified by high resolution chromoendoscopy with indigo carmine dye. For the remaining polyps, the sensitivity, specificity, and negative predictive value of indigo carmine dye staining for adenomatous polyps were, respectively, 82%, 82%, and 88%. The results were consistent among the academic centers and the primary care practice. CONCLUSIONS: High-resolution chromoendoscopy with indigo carmine dye demonstrates morphologic detail of diminutive colorectal polyps that can reliably be used to separate adenomatous from nonadenomatous polyps.

Adenoma↗
PubMed1998

Proton pump inhibitor-associated gastric polyps: a retrospective analysis of their frequency, and endoscopic, histologic, and ultrastructural characteristics.

Since 1992 there have been reports of proton pump inhibitors being associated with fundic gland-type gastric polyps. Endoscopic and histologic characteristics and natural history of these polyps have not been clearly defined. We performed a retrospective study of patients on long-term treatment with proton pump inhibitors who developed gastric polyps. Gastric polyps developed in 17 (10 males and 7 females, 7.3%) of the 231 patients who underwent 2 or more upper endoscopies for complicated gastroesophageal reflux disease and who were receiving long-term treatment with proton pump inhibitors. The mean interval of proton pump inhibitor use after which an endoscopy revealed gastric polyps was 32.5 months. In 1 patient, discontinuation of treatment resulted in disappearance of the polyps within 3 months. The polyps recurred 4 months after the treatment was restarted. Endoscopy established that typical polyps were generally small (<1 cm), sessile, multiple, and whitish pink with a mottled partially translucent surface. The polyps were most often present in the proximal/midgastric body. Of the 15 polyps removed endoscopically, 9 were of the fundic gland type, 4 were of the hyperplastic type, and 2 were of the inflammatory type. Eight of 9 polyps with typical endoscopic appearance were of the fundic gland type. None of the polyps contained dysplasia or carcinoma. Long-term use of proton pump inhibitors may be associated with the presence of small gastric fundic gland polyps and hyperplastic polyps. A prospective study is required to establish their incidence, natural history, and clinical significance.

Endoscopy, Digestive System↗
PubMed2003

Morphologic reappraisal of serrated colorectal polyps.

The "hyperplastic polyp" is considered a benign lesion with no malignant potential, whereas "serrated adenoma" is a precursor of adenocarcinoma. The morphologic complexity of the serrated adenoma varies from being clearly adenomatous to being difficult to distinguish from hyperplastic polyp, which creates a need for more detailed morphologic analysis of all serrated polyps. We evaluated 24 morphologic variables in 289 serrated polyps from the colon and rectum. Cluster analysis and discriminant analysis were performed. A subset of polyps was immunostained for hMLH1 and hMSH2. Major differences were found between right-sided and left-sided polyps. A distinct group of serrated polyps with abnormal proliferation was identified throughout the colon and rectum. These polyps demonstrated decreased expression of hMHL1 and hMSH2 compared with polyps with normal proliferation. Left-sided serrated polyps with normal proliferation further clustered into three groups: vesicular cell-type, goblet cell-type, and mucin-poor-type. We recommend evaluation of the localization, size, and morphologic features when serrated polyps are included in colorectal carcinogenesis research. Polyps with abnormal proliferation are similar to the polyps in "hyperplastic polyposis" and, because of their decreased expression of hMLH1 and hMSH2, may be the subset of polyps associated with the development of colorectal carcinoma via the microsatellite instability pathway.

Adaptor Proteins, Signal Transducing↗
PubMed2005

Occurrence and risk factors for benign epithelial gastric polyps in atrophic body gastritis on diagnosis and follow-up.

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.

Adolescent↗
PubMed2002

Acquired hyperplastic gastric polyps in solid organ transplant patients.

OBJECTIVE: We report a series of patients who developed hyperplastic gastric polyps after solid organ transplantation. METHODS: A retrospective review of patients with solid organ transplantation from January 1997 to December 1999 was performed. Patients with gastric polyps found during endoscopy were included. Demographic data, polyp characteristics (endoscopic and histological), time of endoscopy, and treatment regimens were analyzed. RESULTS: A total of 10 (seven men, three women) transplanted patients (six cardiac, three liver, and one kidney) with gastric polyps were identified. The median age was 61 yr (27-71 yr), and median time of endoscopy after transplantation was 11 months (3-28 months). Eight patients had endoscopy before or soon after transplantation, with no evidence of polyps. Nine patients had multiple polyps (three or more), and one had a single pedunculated polyp. Polyps were confined to the antrum in eight patients, antrum and body in one patient, and fundus in one patient. All polyps biopsied were found to be hyperplastic and without adenomatous or malignant changes. Cytomegalovirus serology was negative in nine patients. Each patient received standard immunosuppression that included a calcineurin inhibitor and steroids. Steroids were tapered and stopped by 3 months. Azathioprine was added in five patients and mycophenolate mofetil in one patient. CONCLUSIONS: The development of gastric polyps after organ transplantation has not been previously reported. The development of these gastric polyps (hyperplastic and multiple) is concerning as a malignant potential has been recognized in patients harboring multiple hyperplastic gastric polyps. The exact cause of these polyps is unknown. The association with immunosuppressive therapy as well as the natural history of these acquired hyperplastic gastric polyps needs further investigation.

Adult↗
PubMed2005

Characteristics of familial juvenile polyps expressing cyclooxygenase-2.

OBJECTIVES: Familial juvenile polyposis (FJP) is a dominant genetic disorder characterized by colorectal, gastric, and small bowel juvenile polyps, and high risk for gastrointestinal cancer. Patients are treated by repeated endoscopic polypectomies and elective surgery. We determined the characteristics of FJP polyps expressing cyclooxygenase-2 (COX-2). METHODS: A total of 115 colorectal and 6 gastric polyps were available from 17 FJP patients. Comparison tissues were 18 sporadic juvenile colorectal polyps, 6 gastric hyperplastic polyps, 9 normal colons, and 3 colorectal cancers (CRCs). Histology sections were classified and stained for COX-2. The polyps' epithelium and stroma and comparison tissues were quantified for COX-2 by: area of staining (0-3) x intensity (0-3). Epithelial and stromal scores (0-9) and total scores (0-18) were evaluated in relationship to patient's age, polyp site, size, dysplasia, and stromal cellularity. RESULTS: Colonic FJP polyps mean total COX-2 score was 10.3 +/- 6.0, and that of sporadic juvenile polyps 3.6 +/- 2.2 (p < 0.01), and in contrast to the latter, FJP COX-2 scores increased significantly (p < 0.01) with polyp size. Linear regression analysis showed significant associations of COX-2 in FJP polyps with dysplasia (p < 0.01), stromal cellularity (p < 0.01), size (> or =1.5 cm) (p= 0.02), and site (right colon) (p= 0.01), and not with age. COX-2 total scores of gastric FJP polyps and hyperplastic polyps were similar. CONCLUSIONS: Expression of COX-2 in FJP polyps and its association with size and dysplasia suggest that, in these patients, chemoprevention with selective COX-2 inhibitors might be a useful adjunct therapy to colonoscopic polypectomy.

Adenomatous Polyposis Coli↗
PubMed2006

Massive-training artificial neural network (MTANN) for reduction of false positives in computer-aided detection of polyps: Suppression of rectal tubes.

One of the limitations of the current computer-aided detection (CAD) of polyps in CT colonography (CTC) is a relatively large number of false-positive (FP) detections. Rectal tubes (RTs) are one of the typical sources of FPs because a portion of a RT, especially a portion of a bulbous tip, often exhibits a cap-like shape that closely mimics the appearance of a small polyp. Radiologists can easily recognize and dismiss RT-induced FPs; thus, they may lose their confidence in CAD as an effective tool if the CAD scheme generates such "obvious" FPs due to RTs consistently. In addition, RT-induced FPs may distract radiologists from less common true positives in the rectum. Therefore, removal RT-induced FPs as well as other types of FPs is desirable while maintaining a high sensitivity in the detection of polyps. We developed a three-dimensional (3D) massive-training artificial neural network (MTANN) for distinction between polyps and RTs in 3D CTC volumetric data. The 3D MTANN is a supervised volume-processing technique which is trained with input CTC volumes and the corresponding "teaching" volumes. The teaching volume for a polyp contains a 3D Gaussian distribution, and that for a RT contains zeros for enhancement of polyps and suppression of RTs, respectively. For distinction between polyps and nonpolyps including RTs, a 3D scoring method based on a 3D Gaussian weighting function is applied to the output of the trained 3D MTANN. Our database consisted of CTC examinations of 73 patients, scanned in both supine and prone positions (146 CTC data sets in total), with optical colonoscopy as a reference standard for the presence of polyps. Fifteen patients had 28 polyps, 15 of which were 5-9 mm and 13 were 10-25 mm in size. These CTC cases were subjected to our previously reported CAD scheme that included centerline-based segmentation of the colon, shape-based detection of polyps, and reduction of FPs by use of a Bayesian neural network based on geometric and texture features. Application of this CAD scheme yielded 96.4% (27/28) by-polyp sensitivity with 3.1 (224/73) FPs per patient, among which 20 FPs were caused by RTs. To eliminate the FPs due to RTs and possibly other normal structures, we trained a 3D MTANN with ten representative polyps and ten RTs, and applied the trained 3D MTANN to the above CAD true- and false-positive detections. In the output volumes of the 3D MTANN, polyps were represented by distributions of bright voxels, whereas RTs and other normal structures partly similar to RTs appeared as darker voxels, indicating the ability of the 3D MTANN to suppress RTs as well as other normal structures effectively. Application of the 3D MTANN to the CAD detections showed that the 3D MTANN eliminated all RT-induced 20 FPs, as well as 53 FPs due to other causes, without removal of any true positives. Overall, the 3D MTANN was able to reduce the FP rate of the CAD scheme from 3.1 to 2.1 FPs per patient (33% reduction), while the original by-polyp sensitivity of 96.4% was maintained.

Algorithms↗
PubMed1999

Immunolocalization of beta catenin in intestinal polyps of Peutz-Jeghers and juvenile polyposis syndromes.

AIM: To examine the membranous and nuclear distribution of beta catenin in the epithelial cells of gut polyps from Peutz-Jeghers syndrome and juvenile polyposis in comparison with other types of polyps and tumours. METHODS: Immunohistochemistry for beta catenin and proliferation markers was performed on conventional paraffin sections. Immunohistological staining was carried out on Peutz-Jeghers syndrome polyps from four different families, on juvenile polyposis polyps from two different families, on solitary juvenile polyps, and on hyperplastic polyps. The immunohistochemistry was evaluated qualitatively in relation to defined areas of the polyps. RESULTS: All polyps from the hamartomatous polyposis syndromes (Peutz-Jeghers syndrome and juvenile polyposis) showed nuclear localization of beta catenin in some epithelial cell nuclei. In Peutz-Jeghers syndrome polyps beta catenin positive nuclei were seen at the base of the deep crypt infoldings. In juvenile polyposis polyps and in some solitary juvenile polyps they were found in irregularly distributed cryptal epithelial cells corresponding to the proliferative compartments. Normal mucosa of the gut and hyperplastic polyps of the colon do not show nuclear staining for beta catenin. CONCLUSIONS: The dysregulation of cellular beta catenin distribution is not only a phenomenon of adenoma formation and adenoma progression in the colon--it is at least focally present in polyps of the hamartomatous type and is related to the proliferation zones of these polyps. The nuclear translocation of beta catenin most probably reflects a disturbed beta catenin metabolism. In view of the different functions of beta catenin during development and cell differentiation, the nuclear translocation of beta catenin is likely to be an important factor in enhanced cell proliferation which escapes local control mechanisms.

Adenocarcinoma↗
PubMed1997

Significance of histologic criteria for the management of patients with malignant colorectal polyps and polypectomy.

BACKGROUND: The management of invasive cancer in colorectal polyps (malignant polyps) is controversial, particularly with regard to the different sets of histologic criteria for deciding whether malignant colorectal polyps should be treated by polypectomy alone or be followed by surgical resection. We report on the outcome of patients in accordance with the histologic assessment of their malignant polyps. METHODS: Malignant polyps were defined as having favourable histology (free margin, grade I or II, and no angiolymphatic invasion) or unfavorable histology (no free margin, grade III, or angiolymphatic invasion). Malignant polyps with favourable histology were treated by endoscopic polypectomy alone, whereas further therapy was recommended for malignant polyps with unfavourable histology. Residual cancer in a resection specimen and local or metastatic recurrence during the follow-up period (mean, 60 months; range, 12 - 120) were defined as adverse outcome. RESULTS: Thirty-seven malignant polyps were detected in 35 (0.5%) of 6605 patients. Five of these 35 patients were treated by primary bowel resection and analysed separately. In the other 30 patients the following unfavourable histologic signs were detected in 20 (62.5%) of 32 malignant polyps; no free margin in 16, grade III in 1, and angiolymphatic invasion in 3 polyps. Twelve polyps with favourable histology had no adverse outcome; in contrast, 5 of 20 polyps with unfavourable histology had an average outcome (P < 0.05). CONCLUSIONS: Locally excised malignant polyps without unfavourable histologic signs may not need further surgical treatment; for all other malignant polyps an ensuing bowel resection is recommended.

Adult↗
PubMed2004

Endoscopic resection of large colorectal polyps.

BACKGROUND: Endoscopic polypectomy is a common technique, but there are discrepancies over which treatment--surgical or endoscopic--to follow in case of polyps of 2 cm or larger. OBJECTIVES: To analyse the efficacy and complications of colonoscopic polypectomy of large colorectal polyps. PATIENTS AND METHODS: 147 polypectomies were performed on 142 patients over an eight-year period. The technique used was that of submucosal adrenaline 1:10000 or saline injection at the base of the polyp, followed by resection of the polyp using a diathermic snare in the smallest number of fragments. Remnant adenomatous tissue was fulgurated with an argon plasma coagulator. Lately, prophylactic hemoclips have been used for thick-pedicle polyps. Complete removal was defined as when a polyp was completely resected in one or more polypectomy sessions. Polypectomy failure was defined as when a polyp could not be completely resected or contained an invasive carcinoma. RESULTS: The mean patient age was 67.9 years (range, 4-90 years), with 68 men and 79 women. There were 74 sessile polyps, and the most common location was the sigmoid colon. The most frequent histology was tubulovillous. Most of the polyps (96.6%), were resected and cured. This was not achieved in four cases of invasive carcinoma, and a villous polyp of the cecum. All pedunculated polyps were resected in one session, whereas the average number of colonoscopies for sessile polyps was 1.35 +/- 0.6 (range, 1-4). The polypectomy was curative in all of the in situ carcinomata except one. As for complications, 2 colonic perforations (requiring surgery) and 8 hemorrhages appeared, which were controlled via endoscopy. There was no associated mortality. CONCLUSIONS: Endoscopic polypectomy of large polyps (> or =2 cm) is a safe, effective treatment, though it is not free from complications. Complete resection is achieved in a high percentage, and there are few relapses. It should be considered a technique of choice for this type of polyp, except in cases of invasive carcinoma.

Adolescent↗
PubMed1993

[Correlation between hyperplastic and adenomatous polyps of the colon].

PROBLEM: Although hyperplastic polyps are considered to be non-neoplastic, they nevertheless have a number of characteristics in common with adenomatous polyps. STUDY DESIGN: Since hyperplastic polyps and adenomas frequently occur together, the question arises as to whether hyperplastic polyps, found for example during sigmoidoscopy, might not be an indicator of possibly neoplastic polyps in the more proximal part of the bowel. In a retrospective analysis of first-time total colonoscopies in 685 patients, we investigated the relationship between hyperplastic and adenomatous polyps. RESULTS: Twenty-one patients proved to have only hyperplastic polyps in the rectosigmoid, while 12 of these patients (11.8%) also had adenomatous polyps in the more proximal parts of the colon. In contrast, 30.8% of the patients (n = 109) with rectosigmoidal adenomas also had adenomas in the more proximal colon. Irrespective of histology, as the size of rectosigmoidal polyps increased, so did the percentage of patients with adenomas in the proximal colon--from 22.4% in the case of small polyps not exceeding 5 mm in diameter to more than 31.2% in the case of polyps larger than 5 mm in diameter. When both hyperplastic and adenomatous polyps appeared together, hyperplastic polyps were found in larger numbers in the same or anatomically adjacent segment of the colon. CONCLUSION: The results of this study suggest that the presence of hyperplastic polyps in the rectosigmoid is not associated with an increase in the incidence of proximal adenomas, while rectosigmoidal adenomas must be considered indicators of adenomas in the more proximal parts of the bowel.

Adenomatous Polyposis Coli↗
PubMed1997

Is in vivo measurement of size of polyps during colonoscopy accurate?

BACKGROUND: Accurate measurement of polyp size during colonoscopy is important because of the direct correlation of size with colon cancer. Major studies of colorectal neoplasms have measured polyp size differently. It is also well documented that endoscopists underestimate polyp size frequently. The goal of this prospective study was to determine which one of the five methods of estimating polyp size during colonoscopy is most accurate. METHODS: One hundred colon polyps were measured by means of visual estimation, open biopsy forceps methods, linear probe, a ruler immediately after excision, and after fixation in formalin. The size of the polyps measured outside the body immediately after excision was considered the "gold standard" against which all measurements were compared. RESULTS: Forty-seven polyps were 5 mm or less in diameter, 33 polyps were 5.01 mm to 10 mm, and 20 polyps were more than 10 mm in size. For all polyps the mean difference versus the actual size of the polyps was 3.4% for linear probe, 6.4% for visual estimation, and 12.3% for the forceps. CONCLUSION: Measurement of polyp size by linear probe agreed best with the actual polyp size, followed closely by visual estimation. The open biopsy forceps method was the least accurate.

Adenoma↗