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The effect of eradicating Helicobacter pylori infection on the course of adenomatous and hyperplastic gastric polyps.

OBJECTIVE: Histopathological and clinical data strongly suggest that Helicobacter pylori is the cause of chronic gastritis and peptic ulceration. However, little has been written about the potential causal relation of H. pylori infection to hyperplastic and adenomatous gastric polyps. We therefore carried out a prospective study to determine the effect of eradicating H. pylori infection on the course of hyperplastic and adenomatous gastric polyps. METHODS: From November 1996 to December 1997, 6700 patients who had undergone upper gastrointestinal endoscopy at the two centres in Zagreb, Croatia, were candidates for participation in the study. Hyperplastic and adenomatous polyps were diagnosed on a basis of at least three histological samples taken from the polyp. In seven patients endoscopy had to be repeated because forceps biopsy sampling either provided inadequate tissue for correct histological diagnosis, or accurate characterization of gastric polyp histology was not possible. Upon completion of all endoscopic examinations before and after treatment, biopsy samples were taken from the antrum (two) and the body of the stomach (two) so that gastritis could be graded and classified, and the presence of H. pylori sought by histology. Two other samples were taken from the antrum for a rapid urease test. Follow-up examinations were performed by using endoscopy. Control endoscopy was performed at least 4 weeks after the treatment of H. pylori infection had been completed, and then every 3-4 months. The follow-up ranged from 4 to 17 months, with a median of 14 months. The treatment of H. pylori infection consisted of a 1-week course of either omeprazole (20 mg twice daily) or pantoprazole 40 mg twice daily), and a 1-week course of amoxicillin 2g twice daily) and metronidazole (400 mg three times daily), and clarithromycin (500 mg twice daily). Eradication of H. pylori infection was assessed by repeated histology and rapid urease test. RESULTS: Twenty-one patients (nine women, 12 men; median age 52 years) with histologically proven hyperplastic gastric polyps, and seven patients (two women, five men; median age, 67 years) with adenomatous gastric polyps were included in the study. Among 21 patients with hyperplastic gastric polyps, 16 patients (76%) were positive for H. pylori infection. Only two patients (29%) with adenomatous gastric polyps were positive for the infection. Complete eradication of H. pylori was initially achieved in all patients positive for H. pylori. Total regression of the gastric polyps was observed only among the patients with hyperplastic gastric polyps in whom H. pylori had been eradicated. Complete regression of the hyperplastic gastric polyps was observed in seven of the 16 evaluable patients (44%; 95% CI, 19-68%) after H. pylori eradication. The endoscopic snare polypectomy was carried out in nine patients with hyperplastic polyps and two patients with adenomatous gastric polyps in whom regression of the polyps was not observed after H. pylori eradication, as well as in five patients with hyperplastic and four with adenomatous gastric polyps who were negative for H. pylori. Exploratory laparotomy and gastrotomy with polyps excision were carried out in one patient with multiple adenomatous gastric polyps. In only one patient who was not positive for H. pylori recurrence of hyperplastic gastric polyp was recorded during follow-up, and no re-infection with H. pylori has been detected. CONCLUSIONS: Our results suggest that the development of hyperplastic gastric polyps may be directly related to chronic active gastritis and concomitant H. pylori infection. Cure of H. pylori infection associated with hyperplastic gastric polyps resulted in complete polyp regression in more than 40% of patients. Therefore, for patients with hyperplastic gastric polyps and concurrent H. pylori infection an antibiotic treatment designed to eradicate H. pylori appears to be recommended before further therapeutic options are consi

Adenomatous Polyps↗

Experience in the endoscopic management of large colonic polyps.

BACKGROUND: Large colonic polyps present a particular challenge to endoscopists because of the risks of significant haemorrhage, perforation, inadequate polypectomy, or trying to snare an unrecognized cancer. The alternative to endoscopic therapy of large polyps is surgical resection and although minimally invasive techniques are available, risks are significant. Although neither surgery nor endoscopy is a perfect way of treating large colonic polyps, endoscopic resection is usually tried first. Most series of endoscopic polypectomies are small, include both rectal and colonic polyps and have varying size and shape criteria. The purpose of the present study is to describe a large consecutive series of colonic polyps evaluated endoscopically, to determine the chances of performing a safe, effective endoscopic polypectomy. METHODS: All colonic polyps>20 mm in maximum dimension assessed during colonoscopy from 1989 to 2002 were reviewed. Rectal polyps were excluded. Demographic data for the patients were abstracted, as were data regarding the outcomes of polyp assessment and treatment. Primary end-points were: the need for surgical resection, the incidence of postpolypectomy complications and the persistence of the index polyp at follow up. Independent variables included the endoscopically assessed size of the polyps, the year in which the polypectomy took place, the shape of the polyps and their location within the colon. RESULTS: During the period under review 311 large polyps were removed from 252 different patients. Of these, 263 polyps were removed endoscopically and 48 polyps were removed surgically. An additional 18 endoscopically removed polyps ultimately needed surgery for recurrence or malignancy. There were no deaths but 19 complications of endoscopic polypectomy (17 late haemorrhage and two postpolypectomy syndrome). At first follow up, 22% of polyps had persisted, this decreased to 14% at second follow up and 7% at third. Complications were more common in right sided polyps and in flat or sessile lesions. Pedunculated polyps never persisted or recurred and had the lowest rate of surgery. Larger polyps had higher rates of advanced histology, complications, polyp persistence and the need for surgery. CONCLUSIONS: Polyp size, location and shape influence the results of endoscopic resection of large colonic polyps. Polyps>30 mm in maximum diameter are significantly more advanced histologically but also significantly more difficult to treat successfully than those <30 mm. However, size alone is rarely a contraindication to endoscopic resection.

Aged↗

Small colorectal polyps: histopathology and clinical significance.

OBJECTIVES: The development of colorectal adenomas and carcinoma involves both environmental and genetic factors. Wide variations among populations have been observed in the prevalence of adenoma. Investigations of the small colorectal polyps have been divergent. The distribution of these small polyps remains in controversy. The histology, clinical significance, and optimal treatment of such lesions have yet to be defined. The aim of the present prospective study is to ascertain the importance of small colorectal polyps in the Taiwanese and to define their histopathological nature, spatial distribution, and clinical significance. METHODS: We prospectively evaluated all patients referred for colonoscopy for miscellaneous indications. All raised lesions encountered during the procedure were removed or biopsied. Each polyp was estimated in situ by visual comparison with the known width of a standard fully opened biopsy forceps. Small colorectal polyps were defined as those measuring 8 mm or less in diameter. Histopathology of these small polyps were reviewed and correlated clinically. RESULTS: 124 patients were found to have 159 small colorectal polyps. There were 88 men (71%) and 36 women (29%). The mean ages were 60.2 yr for men and 50.8 yr for women. Solitary polyps were present in 68.5% of patients while 26.6% had two polyps and 4.9% had between 3 and 10 polyps; 60.4% of the small polyps were neoplastic, while 39.6% including 23.9% hyperplastic polyps were nonneoplastic; 50.3% of the small polyps were located in the rectosigmoid. Tubular adenomas accounted for 90.6% of the small neoplastic polyps. The neoplastic polyps predominated in each colorectal segment. The proportion of small neoplastic polyps was higher in older patients; 2.8% of the small adenomas showed moderate dysplasia. Severe dysplasia was noted in only one polyp. No malignancy was observed. The chi-square test with Yates' correction was used for statistical analysis. CONCLUSIONS: These findings reveal that a large share of the small colorectal polyps are neoplastic and therefore at risk to progress to carcinoma. The location of small polyps distributed at the rectosigmoid or the proximal colon was of no significance (p > 0.2) for the proportion of neoplastic polyps. The older patients probably have higher risk because of their higher proportions of small neoplastic polyps. All polyps should be removed when encountered during colonoscopy due to the high prevalence of adenomas among small colorectal polyps.

Adult↗

Colon polyp retrieval after cold snaring.

BACKGROUND: The removal of small colon polyps by cold snare transection without electrocautery effectively eliminates polyps, and anecdotal reports indicate a low risk of bleeding and perforation. Concerns about using cold snaring have centered on the risk of immediate bleeding and the difficulty in retrieving the polyp. The objective was to determine the retrieval rates of polyps after cold snaring after two different methods of resection and retrieval. METHODS: Consecutive polyps were identified by a single colonoscopist who chose the technique of polypectomy (hot snare, cold snare, or cold forceps). If cold snaring was chosen, an independent observer assigned the polyp to method A (cold resection of polyp without tenting and then suction of the transected polyp into a trap) or method B (ensnare the polyp, pull it into the colonoscope channel, and then transect it while suctioning). The size and the approximate location of all polyps were recorded and all collected specimens were sent separately for histologic examination. Results Of 519 consecutively encountered polyps, 400 were removed by cold snare: 197 were assigned to method A and 203 to method B. The mean size of polyps that were cold snared was 3.5 mm. The mean time to remove and to retrieve polyps with method A was 14.5 seconds (n = 58) and with method B was 18.1 seconds (n = 60) ( p = 0.03). There were no complications from cold snaring. The rate of successful retrieval with method A was 100% (197 of 197 polyps) and with method B was 98% (199 of 203 polyps) ( p = 0.04). CONCLUSIONS: Cold snare removal of colon polyps is associated with a high polyp retrieval rate. Each of two methods of polyp retrieval was effective. Snare transection without tenting of the polyp, followed by suctioning of the specimen off the polyp site, was more efficient, though the difference in efficiency was minimal. Difficulty or failure to retrieve polyps should not be a concern with regard to cold snare polypectomy.

Cold Temperature↗

The changed histologic paradigm of colorectal polyps.

BACKGROUND: Previous literature has recorded the preponderance of hyperplastic over neoplastic polyps. This study evaluated the histopathologic characteristics of colonic polyps, excised during colonoscopic polypectomy, and further determined their relationship to age, location, and gender. METHODS: Of 5132 colonoscopies reviewed between 1976 and 1999, 757 were performed on 582 patients who had polyp removal. Patients with previous colon resection or incomplete cecal intubation were excluded. RESULTS: The mean age was 67 +/- 11 years for men and 66 +/- 11 years for women. Of the 1050 lesions histologically analyzed, 871 (83.0%) were neoplastic, 129 (12.3%) were hyperplastic, and 50 (4.8%) were miscellaneous lesions (29 inflammatory polyps, 14 lipomas, 2 leiomyomas, 1 juvenile polyp, and 4 no pathology identified). Hyperplastic polyps were always less than 1 cm (with one exception) and were located predominantly in the left colon, the majority residing in the sigmoid colon. Peak prevalence of hyperplastic polyps occurred in the 50-70 years old age group. Of the neoplastic polyps, 566 (65.0%) were tubular, 225 (25.8%) villotubular, 63 (7.2%) villous adenomas, 4 (0.5%) mixed adenomatous hyperplastic polyps, and 12 (1.4%) invasive carcinomas. The peak prevalence of neoplastic polyps occurred in the same age group as did hyperplastic polyps. Even though adenomatous polyps outnumbered hyperplastic polyps throughout the colon and within each age group, a greater percentage of hyperplastic polyps were found distally and in younger patients compared to location and age groups for neoplastic polyps. CONCLUSION: Adenomatous polyps outnumber hyperplastic polyps 7:1, even in the distal colon. Even small polyps seen during colonoscopy should be removed and subjected to histologic analysis because of the advisability of follow-up examinations of patients with neoplastic polyps. The increase in the incidence of neoplastic polyps beginning at the age of 50 years supports the need for colonoscopy in these individuals.

Adenomatous Polyps↗

Follow-up colonoscopy in patients with colorectal adenomatous polyps.

Forty-four asymptomatic patients with adenomatous colorectal polyps were followed by repeated colonoscopies and subsequent removal of new polyps. The median follow-up time was 34 months (range, 4 to 131 months). Twenty-six patients (59 percent) developed new adenomatous polyps. The recurrence rate was 69 percent in patients with multiple polyps compared with 54 percent in patients with a single polyp. The location of new polyps was in the same colonic segment in 81 percent of the patients, but not at the same site in the colon where a previous polyp had been removed. The histopathology and size of new polyps compared with the initial polyps showed a significant improvement in histopathology toward more benign polyps (P less than 0.02) and smaller polyps (P less than 0.001). In patients who initially had single adenomatous polyps, new polyp(s) were diagnosed after a mean time of 23 months compared with 13.5 months in patients with two or more adenomatous polyps initially. Patients with atypia in initial polyp(s) developed new polyp(s) after a mean time of 11 months compared with 23 months in patients without atypia. The mean time from a colon with no polyps to the diagnosis of a new adenomatous polyp less than 5 mm in size was 11.5 months, which was a statistically significant shorter time than the 19.4 months observed for the development of polyps 5 mm or larger.

Adult↗

Prevalence of advanced colonic polyps in asymptomatic Chinese.

AIM: To investigate the prevalence of advanced polyps in asymptomatic Chinese and to determine the risk of proximal advanced colonic polyps in subjects with and without polyps in the distal colon. METHODS: Data were collected prospectively during colonoscopic examinations performed in 5 973 subjects as part of health evaluation at our unit from December 1997 to December 2003. Polyps were considered advanced, if they were larger than 10 mm or were tubovillous, villous or malignant. Proximal colon was defined as the splenic flexure and more proximal portions of the colon. RESULTS: Colon polyps were detected in 971 (16.3%) subjects (613 males and 358 females) with their mean age being 56.6+/-10.7 years. Advanced polyps were noted in 199 (3.3%) individuals. Subjects were sub-classified according to the location of polyps into three groups: distal (569, 58.6%), proximal (284, 29.2%), and combined proximal and distal (118, 12.2%) groups. Subjects with advanced polyps in these three groups were 95 (9.8%), 56 (5.8%), and 48 (4.9%) respectively. In the 48 subjects with advanced combined polyps, 13 advanced polyps were distributed at the distal colon, 17 at the proximal colon, and 18 at both. Eighteen colon cancers including 12 at sigmoid and 6 at ascending colon were confirmed by final pathology. The relative risk for advanced proximal polyp according to distal findings was 3.1 (95%CI: 1.3-7.4) for hyperplastic polyp, 2.7 (95%CI: 1.4-5.3) for tubular polyp and 13.5 (95%CI: 5.1-35.4) for advanced polyp as compared to that for no polyp. However, 56 (28.2%) of 199 subjects with advanced polyps had no index polyps at the distal colon and might go undetected under sigmoidoscopic screening. CONCLUSION: Although distal lesions can predict the risk of advanced proximal polyps, a substantial portion of Chinese with advanced proximal polyps is not associated with any distal sentinel lesions. These data have implications for screening policy of colon cancers in Taiwanese Chinese.

Adult↗

Vascular endothelial growth factor and children featuring nasal polyps.

BACKGROUND: The aim of this study is to explore the expression of vascular endothelial growth factor within nasal polyps, and the implication of such expression as regards the development of nasal polyps amongst children. MATERIAL AND METHODS: Sixty children suffering from chronic rhinosinusitis were enrolled in this study. Amongst them, 30 patients featured rhinosinusitis with associated nasal polyps. A biopsy specimen was taken from the stalk or the base of the nasal polyp for nasal-polyp sufferers, and the ethmoid sinus for study participants who featured no nasal polyps. The primary lesions biopsied were immunohistochemically stained with a specific endothelial-cell marker and also stained for the presence of vascular endothelial growth factor. The specific level of vascular endothelial growth factor and the mean number of blood vessels present in a visual microscopic (biopsied-specimen) field were calculated under light microscopy (x400). RESULTS: The number of vascular endothelial growth factor-expressing cells for the nasal-polyp group and for the sinusitis group was, respectively, 20.8+/-4.0 and 11.5+/-3.4 per visual field. Correspondingly, the mean intra-polyp blood-vessel density for the nasal-polyp group and that for the control group was, respectively, 10.5+/-2.6 and 5.0+/-1.9 per visual field. The mean intra-polyp blood-vessel density and the number of vascular endothelial growth factor-expressing cells proved to be significantly greater amongst individuals from the nasal-polyp group than was the case for their analogs from the sinusitis group (P<0.01, for both). The presence of vascular endothelial growth factor was found to be distributed predominantly within the vascular endothelium and the mast cells of polyp tissue. In addition, the level of vascular endothelial growth-factor expression and the mean blood-vessel count per field correlated significantly for nasal-polyp tissue (P<0.001). Furthermore, the relative size of nasal polyps correlated significantly with the number of (intra-polyp) vascular endothelial-cell growth factor-expressing cells and the mean blood-vessel density (P<0.05, for both). CONCLUSION: The level of expression of vascular endothelial-cell growth factor (VEGF) and the mean blood-vessel density were shown to be significantly greater within nasal polyps than within corresponding sinusitis mucosa. Clinically, the expression of both of these parameters correlated well with the relative size of nasal polyps. Vascular endothelial growth factor participates in the formation of nasal polyps amongst children suffering from chronic rhinosinusitis (CRS).

Adolescent↗

Molecular alterations in chronic ulcerative colitis-associated and sporadic hyperplastic polyps: a comparative analysis.

OBJECTIVES: There is growing interest in the biological and molecular features and neoplastic potential of colonic hyperplastic polyps because of the recent finding of K-ras mutations in many of these lesions. Hyperplastic polyps may also develop in chronic ulcerative colitis (CUC), but it is unclear if these are biologically similar to the sporadic type. The aim of this study was to evaluate and compare the molecular profile of CUC-associated hyperplastic polyps with sporadic hyperplastic polyps of the colon. METHODS: Thirty-nine hyperplastic polyps from 26 CUC patients, 39 sporadic hyperplastic polyps from 29 age- and sex-matched patients without CUC, and 26 colonic mucosal biopsies from 22 patients with CUC but without hyperplastic polyps were analyzed by polymerase chain reaction for loss of heterozygosity of APC, 3p, p53, and p16 and for mutations in codons 12, 13, and 61 of the K-ras gene. Immunohistochemical evaluations for the proliferation-associated nuclear peptide Ki67 (MIB-1) and p27 were also performed on a subset of hyperplastic polyps. RESULTS: CUC-associated hyperplastic polyps showed a proportion of genetic alterations (47%) similar to that of sporadic hyperplastic polyps (33%) (p > 0.05), and neither significantly differed from chronically inflamed mucosae in CUC patients without hyperplastic polyps. Furthermore, in a small group of CUC patients in which informative tissue was available from both their hyperplastic polyps and adjacent flat colitic mucosae, the polyps contained mutations that were not present in the underlying mucosa. Loss of heterozygosity of APC, 3p, p53, p16, and K-ras mutations were present in 21%, 40%, 27%, 20%, and 19% of CUC patients with hyperplastic polyps, respectively, and in 0%, 11%, 20%, 13%, and 13% of non-CUC patients with sporadic polyps, respectively. Both CUC-associated and sporadic hyperplastic polyps showed a substantial number of cases (46% and 64% of cases, respectively) with loss of p27 expression, and both types of lesions showed similar MIB-1 proliferation indices. CONCLUSIONS: These data suggest that CUC-associated hyperplastic polyps are genotypically similar to the sporadic type. This study adds to the expanding list of molecular alterations that have been discovered in hyperplastic polyps, and lends further support to the controversial theory that these lesions may have neoplastic potential.

Chromosomes, Human, Pair 3↗

Endoscopic snare resection of large colonic polyps: how far can we go?

BACKGROUND AND AIMS: Colonoscopic polypectomy is preventing colorectal cancer. Videoendoscopy and new perendoscopic hemostasis techniques make endoscopic polypectomy of large colonic polyps an alternative to the surgical approach. This study examined whether complete snare resection of giant colonic polyps is feasible and safe and for determining how often surgery is necessary due to invasive cancer detected histologically after polypectomy. PATIENTS AND METHODS: The study included 59 consecutive patients with 68 colonic polyps larger 30 mm in diameter. Snare polypectomy was performed after an endoscopic ultrasound with a miniprobe found no sign of invasive, or, depending on the appearance of the polyp, a bleeding prophylaxis had been carried out. Acute procedural or delayed bleeding was treated endoscopically. RESULTS: Of the 68 polyps 26, mostly pedunculated were resected en bloc (38%) and histologically ensured as completely resected; 42 polyps had to be resected by piecemeal technique (62%). Piecemeal resection was performed significantly more often in sessile polyps (38/41, 93%) than in pedunculated polyps (4/27, 15%, P<0.01). Follow-up colonoscopy after 3 months showed remaining adenomatous tissue of piecemeal-resected polyps in 12 cases (28%), which were 12 resected sessile polyps (29%) and no case of resected pedunculated polyp. To achieve complete resection of sessile polyps a second procedure was necessary significantly more often than for resection of pedunculated polyps (12 cases in sessile polyps, 18% vs. no case in pedunculated polyps). Remaining adenomatous tissue was removed in all 12 cases during the first follow-up colonoscopy after 3 months, confirmed by a biopsy 6 months after the initial procedure. Overall coexisting malignancy was found in only 7 polyps (12%). Due to high-risk factors only one of them underwent secondary surgical procedure. CONCLUSION: The present study shows that endoscopic snare resection of giant colonic polyps is a safe procedure, and that secondary operative measures for managing coexisting malignancy are rarely necessary.

Adenomatous Polyps↗

The pathologic measurement of polyp size is preferable to the endoscopic estimate.

BACKGROUND: There is no standardized technique to measure polyp size. Estimation of polyp size at endoscopy is difficult. Polyp size measurement by pathologists would seem to be an accurate alternative, but tissue fixation may alter polyp size. To evaluate methods of determining polyp size, we compared endoscopists' estimates and pathologists' measurements with measurements made by an independent examiner. METHODS: Polyps were measured by an independent investigator before and after formalin fixation. The investigator's measurement before fixation (the "gold standard") was compared with the endoscopists' estimates and the pathologists' measurements. RESULTS: Ten endoscopists removed 61 polyps with a snare in 33 patients: 82% were adenomatous and 72% were pedunculated. Mean size was 0.85 +/- 0.6 cm (SD) (range: 0.3 to 3.6 cm, 26% > or = 1 cm). Polyps remained in formalin for a mean of 239 minutes (46 to 1164 minutes). Polyps neither consistently shrank nor enlarged in formalin (maximum change +/- 0.2 cm, r = 0.99 [p < 0.001]). Interobserver agreement between pathologists' and the investigator's post-formalin measurements showed that 55 of 57 polyps (97%) were within +/- 0.3 cm. Endoscopists inaccurately estimated 11 of 56 polyps (20%) (> 0.3 cm difference from the independent examiner). Polyp size was underestimated in three instances (range 0.5 to 0.9 cm) and overestimated in eight (range 0.4 to 0.8 cm). In 5 of 11 instances (46%), this inaccuracy altered polyp size classification across the 1 cm threshold. Results were not dependent on endoscopist, histology, or polyp location. CONCLUSIONS: (1) Polyp size is not significantly affected by formalin fixation; 2) Endoscopists' estimates of polyp size are often unreliable; and, when possible, (3) Pathologists' measurements of polyp size should be used in clinical trials and in clinical practice.

Adenomatous Polyps↗

Interleukin 5, IL6, IL12, IFN-gamma, RANTES and Fractalkine in human nasal polyps, turbinate mucosa and serum.

Polyps are considered to develop as an end result of an inflammatory process. Cytokines and chemokines in the respiratory mucosa may be a key to polyp pathophysiology. The main objective was to identify IL-5, IL-6, IL-12, RANTES, IFN-gamma and Fractalkine in humans on the protein level in nasal polyps and mucosa from the inferior turbinate (IT). Furthermore, the cytokines and chemokines RANTES and Fractalkine were analyzed in plasma. Tissue homogenates and plasma from 13 patients were analyzed by the ELISA technique. All the patients had longstanding nasal/paranasal polyposis. Fractalkine was detected in polyps and IT in two different patients. IL-5 was expressed in polyps and IT. IL-6 was expressed in all patients with a higher level in polyps than IT. IL-12 was present in plasma, polyps and IT, though at an increased level in polyps. RANTES was present at a higher level in plasma than in polyps and IT. IFN-gamma was detectable in polyps and IT. Fractalkine is detected in nasal polyps, which is a new observation. The overall results indicate a mixed T(H)1/T(H)2 cytokine profile in nasal polyps. RANTES and IL-12 are strongly present in plasma, suggesting an ongoing inflammatory "drive". IL-6 and IL-12 are up-regulated in polyps versus the IT. Up-regulation of IL-6 may be explained by increased fibroblast activity dependant on an ongoing local inflammation possibly initiated by an infection. IL-5, RANTES and IFN-gamma are equally represented in polyps and IT, indicating equilibrium between the nasal polyps and surrounding tissue, and that an up-regulation of cytokines in the polyp indicates a potential for polyp growth.

Adult↗

[Distribution of polyps in the inside region of Vizcaya (Spain): implications for diagnostic tests and colorectal cancer screening].

INTRODUCTION: The importance of colonic polyp is increasing because colorectal cancer (CRC) screening is based on their identification. However, consensus is lacking on which technique should be used in CRC screening, whether colonoscopy or other methods such as sigmoidoscopy, which shows good sensitivity only in distal segments of the colon. We studied the characteristics and localization of polyps in our environment to verify their tendency to change localization and determine the implications of this in screening. MATERIAL AND METHODS: We reviewed the prevalence and characteristics of colonic polyps in 3604 patients who underwent colonoscopy for various causes in our service, as well as their distribution in 837 patients with a diagnosis of polyps who underwent complete colonoscopy. Localization proximal or distal to the splenic flexure and polyp size (less than or more than 1 cm) were analyzed. RESULTS: Polyps were found in 28.3% of 3604 patients (11.7% showed polyps > or = 1 cm). Of the 837 patients who underwent complete colonoscopy, proximal polyps were found in 44.9% (14.6% showed polyps > or = 1 cm), while distal polyps were found in 79.9% (30.3% showed polyps > or = 1 cm). Both proximal and distal polyps were found in 24.8%. The probability of finding both proximal and distal lesions was 31%. Proximal lesions without distal lesions were found in 20% of the patients (5.6% presented polyps > or = 1 cm), and consequently sigmoidoscopy would miss 15.6% of polyps > or = 1 cm. CONCLUSIONS: A relatively high percentage of patients with proximal polyps > or = 1 cm would remain undiagnosed if complete colonoscopy were only performed in patients with distal polyps. Because of the well-known increase in the frequency of proximal polyps and because a considerable number of these present without distal sentinel lesions, there are increasing arguments for considering colonoscopy as the basic technique for CRC screening.

Colon↗

Clinical significance of small polyps found during screening with flexible sigmoidoscopy.

In deciding how to interpret the significance and management of small distal adenomatous polyps found on FS, one must first decide on the goal of a screening program. If the goal is maximal reduction of CRC risk, regardless of cost, there is little argument that screening colonoscopy is the most effective approach. Unfortunately cost and cost-effectiveness are important considerations when administering a screening program with a fixed budget. Although comparing the cost-effectiveness of different strategies is beyond the scope of this article, rigorous comparisons by other authors have suggested that a sigmoidoscopy-based approach is more cost-effective than a colonoscopy-based approach. The most cost-effective approach may change, however, if the frequency of screening and surveillance can be reduced without significantly impacting effectiveness. Other authors using assumptions including low compliance rates for regular FOBT or FS have determined that colonoscopy every 10 years is the most cost-effective approach. Multiple studies support the recommendation that villous polyps regardless of size and adenomatous polyps greater than 1 cm found on FS are important markers for the presence of advanced polyps and cancer in the proximal colon. These patients should undergo colonoscopy. If one assumes that a sigmoidoscopy-based approach is reasonable, and accepts that such an approach always misses a small number of proximal lesions, how should one manage patients with a small adenomatous polyp on FS? In aggregate, the studies discussed previously suggest that patients with no distal polyps, distal hyperplastic polyps, or a single small distal tubular adenoma have a similar and low risk of advanced proximal adenomas of the colon. There are some studies, however, that do not support this. With the exception of the study by Read et al, these studies included patients at elevated risk of CRC because of a family history, or inclusion of patients with positive FOBT (or not tested). The study by Read et al also included patients with distal villous adenomas in their low-risk group. Because a sigmoidoscopy-based strategy typically excludes patients at elevated risk, these results may not be applicable to low-risk patients undergoing sigmoidoscopy. Given these caveats, what can one conclude about the predictive value of a small tubular adenoma found on FS? These studies suggest that the risk of proximal advanced polyps is similar or slightly increased in patients with a distal adenoma than those with a negative FS. The risk of finding an advanced adenoma seems to be 0% to 4% regardless of the findings of no polyps, hyperplastic polyps, or small tubular adenomatous polyps on FS in low-risk patients. A small portion of patients with hyperplastic polyps found on FS have advanced proximal adenomas. If a hyperplastic polyp on FS is not an indication for colonoscopy and the risk of proximal advanced adenomas is similar in patients with only a small distal adenoma, it is inconsistent to recommend colonoscopy for a small distal tubular adenoma and not a hyperplastic polyp. Based on the studies of asymptomatic patients with no family history and negative FOBT, the authors believe it is reasonable to defer colonoscopy if no polyp, a hyperplastic, or a small tubular adenoma is found at sigmoidoscopy in low-risk patients. If the patient or physician is unwilling to accept a small (0% to 4%) chance of missing an advanced proximal lesion, then a sigmoidoscopy-based approach (regardless of the threshold to go on to colonoscopy) is not appropriate. Screening FS remains an effective examination to screen for CRC in asymptomatic patients. There is no question that colonoscopy clearly detects more lesions than FS. It remains to be seen if the increase in costs and risks justifies the improved detection rate of colonic polyps. Given manpower issues that face us today, and examining the question from a population perspective, reserving colonoscopy for only those patients with an advanced distal polyp on FS gives the biggest yield.

Colonic Polyps↗

Clinical characteristics of colorectal polyp in Thai children: a retrospective study.

BACKGROUND: It was believed that more than 90 per cent of children with colorectal polyp had a single lesion, located in the rectosigmoid colon, therefore, sigmoidoscopy with polypectomy was the treatment of choice. After a wide use of pediatric colonoscopy, this concept has been changed. MATERIAL AND METHOD: This study was aimed to describe clinical characteristics of colorectal polyp in Thai children. Medical records of children with colorectal polyp were retrospectively reviewed. Comparison between polyposis coli and children with less than 5 polyps were also analyzed. RESULTS: There were 93 patients, 43 females and 50 males. The average age was 5.1 years. Lower GI bleeding and prolapse of rectal polyp comprised the two most common presentations, 93.5 and 39.8 per cent, respectively. The mean duration of symptoms was 5.6 months. Only 50.6 per cent had rectal polyp noted by digital examination. Investigations included sigmoidoscopy (n = 77), colonoscopy (n = 16), and barium enema (n = 16). Eight per cent of the cases had more than 5 polyps. Location of the polyps was noted in the rectosigmoid colon (88.2%), descending colon (4.3%), right-sided colon (4.3%), and pancolonic (3.2%). Of all the patients, 11.8 per cent had the polyp above the rectosigmoid region, whereas 50 per cent of those who underwent colonoscopy (n = 16) had the polyps noted proximal to this region. Older age, lower hematocrit, and more frequent right-sided polyps were significantly associated with polyposis coli (p < 0.05). Only 2 patients with polyposis coli were treated by colectomy. Histopathology included juvenile polyp (95%), inflammatory pseudopolyp (2.5%), and hyperplastic polyp (2.5%). CONCLUSION: Most of the children with colorectal polyp had juvenile polyp that is commonly found in the rectosigmoid colon. However, a significant number of patients had carrying polyps proximal to the rectosigmoid region, which would be easily missed by sigmoidoscopy. With the concern of malignancy change particularly in children with polyposis coli, routine colonoscopy should be considered as an initial investigation in children with colorectal polyp.

Adenomatous Polyposis Coli↗

Multiple large hyperplastic polyps of the colon coincident with adenocarcinoma.

Diminutive hyperplastic polyps are the most common non-neoplastic lesions of the colon. Typically, they are small (< 0.5 cm) sessile lesions, lack cellular atypia, and are found predominantly in the rectosigmoid region of the colon. Multiple large hyperplastic polyps (> 1 cm) are rare. Although the relationship between diminutive hyperplastic polyps and adenomatous polyps or carcinoma is controversial, even less data are available on the significance of large hyperplastic polyps. We report the case of a 56-yr-old man who was seen because of fatigue, anemia, and Hemoccult-positive stool. On air contrast barium enema study and colonoscopy, multiple polyps that were similar in appearance were found distributed symmetrically throughout the colon. However, histologic examination revealed 16 hyperplastic polyps 1-2 cm in size, multiple diminutive hyperplastic polyps, one adenomatous polyp, and one adenomatous polyp containing well-differentiated adenocarcinoma. Because multiple large hyperplastic polyps are rare, we suspect this entity may be distinct from diminutive hyperplastic polyps. In our patient, large hyperplastic polyps were distributed symmetrically throughout the colon and were associated with a synchronous carcinoma. Because large hyperplastic polyps may be coincident with adenomatous polyps and carcinoma of the colon, we recommend that patients found to have large hyperplastic polyps undergo removal of all polyps for histologic study.

Adenocarcinoma↗

Benign epithelial gastric polyps--frequency, location, and age and sex distribution.

Prospective investigation has been undertaken with the aim to study the frequency, location and age and sex distribution of various histological types of benign gastric epithelial polyps. Histological type--adenomatous, hyperplastic and fundic gland polyps--was diagnosed on the basis of at least three histological samples taken from the polyp. Biopsy samples were also taken from the antrum and the body of the stomach so that gastritis could be graded and classified, and the presence of H. pylori could be determined by histology. All 6,700 patients, who had undergone upper gastrointestinal endoscopy in a one-year period, participated in this study. Among them 42 benign gastric epithelial polyp were found in 31 patients: adenomatous gastric polyps in 7 patients, hyperplastic gastric polyp in 21 and fundic gland polyp in 3 patients. All patients with hyperplastic polyps had chronic active superficial gastritis, whereas most of the patients with adenomatous polyps had a chronic atrophic gastritis with high prevalence of intestinal metaplasia. Among 21 patients with hyperplastic gastric polyps, 16 (76%) patients were positive for H. pylori infection in contrast to only 2 patients (29%) with adenomatous gastric polyps and 1 patient (33%) with fundic gland polyp. Presented data indicates that hyperplastic gastric polyps are the most common and they are associated with the presence of chronic active superficial gastritis and concomitant H. pylori infection. Adenomatous polyps are rarer and they tend to be associated with chronic atrophic gastritis and intestinal metaplasia. Fundic gland polyp is the rarest type of gastric polyps.

Adenomatous Polyps↗

Risk of proximal colorectal neoplasia among asymptomatic patients with distal hyperplastic polyps.

PURPOSE: Many guidelines on colorectal cancer screening do not consider distal hyperplastic polyps to be a marker for proximal neoplasia. However, 11 of 17 published studies have shown an increased risk of proximal neoplasia in patients with distal hyperplastic polyps. Our goal is to assess the risk of proximal neoplasia in asymptomatic patients with distal hyperplastic polyps, compared to those with distal tubular adenomas or no distal polyps. METHODS: We assessed proximal (cecum, ascending, transverse colon and splenic flexure) and distal polyps in patients undergoing screening colonoscopy, classifying them into 3 groups: distal hyperplastic polyps only; distal adenomas with or without hyperplastic polyps; no distal polyps. The prevalence of proximal neoplasia and advanced neoplasia (polyps > or =1 cm, villous adenomas, or cancer) was compared among these groups. RESULTS: Of 2357 patients, 427 (18%) had neoplasia, including 103 (4%) with advanced neoplasia. Proximal neoplasia occurred in 175 (9%) of 1896 patients with no distal polyps, compared with 28 (12%) of 237 with distal hyperplastic polyps (P = 0.20) and 64 (29%) of 224 with distal adenomas (P <0.0001). Proximal advanced neoplasia occurred in 39 (2%) patients with no distal polyps, compared with 4 (2%) with distal hyperplastic polyps (P = 0.70) and 9 (4%) with distal adenomas (P = 0.13). CONCLUSIONS: Patients with distal hyperplastic polyps, unlike those with distal adenomas, do not exhibit an increased risk for proximal neoplasia or proximal advanced neoplasia compared to those with no distal polyps. The discovery of hyperplastic polyps on screening sigmoidoscopy should not prompt colonoscopy.

Adenoma↗