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Hitherto unclassified colorectal polyps were identified in 32 patients (23 men and 9 women; mean age, 53 years). The only symptom, which was observed in less than half the patients, was passage of blood or occult blood. Endoscopic examination revealed solitary pedunculated, red polyps with a smooth surface. These polyps were found in the left colon, especially in the sigmoid. Their characteristic features were inflammatory granulation tissue in the lamina propria mucosae, proliferation of smooth muscle, and hyperplastic glands with occasional cystic dilatation. The etiology of this type of polyp is unknown, but it could involve chronic trauma from the fecal stream and from peristalsis of the bowel. These polyps can be differentiated from juvenile polyps and inflammatory polyps by the presence of abundant smooth-muscle cells in the inflamed lamina propria mucosae. They also can be differentiated from Peutz-Jeghers polyps, which appear as hamartomatous structures with tree-like proliferation of muscularis mucosae covered by colonic mucosa without inflammatory granulation tissue. Their locations and macroscopic appearance distinguish these polyps from mucosal prolapse syndrome and polyps developed after colostomy. In addition, these new polyps differ from inflammatory cap polyps in that they lack a fibrin cap. We propose the name inflammatory myoglandular polyps for these polyps, which are distinct clinicopathologically from other types of colorectal polyps.
The National Polyp Study (NPS) is a multicenter prospective randomized trial designed to evaluate follow-up surveillance strategies in patients who have undergone polypectomy for the control of large bowel cancer. The study design was developed by a joint research committee from American Gastroenterological Association, the American Society for Gastrointestinal Endoscopy, and the American College of Gastroenterology. Subjects who met the eligibility criteria were randomized into two different treatment arms. Eligibility criteria included: removal of one or more adenomas; complete colonoscopy; no prior polypectomy, inflammatory bowel disease, or familial polyposis; and no history of colon cancer. The treatment arms consisted of a frequent follow-up (1 and 3 years after initial polypectomy) and a less frequent follow-up (3 years). Follow-up examinations included fecal occult blood tests, air-contrast barium enema, and colonoscopy. The latter was done on 9112 referred patients at the seven participating centers from November 1980 until February 1990 who had no history of polypectomy, colon cancer, familial polyposis, or inflammatory bowel disease. Of these patients, 4763 (52.3%) had no polyps; 549 (6.0%) had an invasive cancer; 776 (8.5%) had nonadenomatous polyps; 208 (2.3%) had incomplete examinations; 184 (2.0%) had other findings; and 2632 (28.9%) had one or more adenomas, of which 1418 (53.9%) were randomized to one of the two treatment arms. This article reports the background, rationale, objectives, methods, and organization of this study and includes patient characteristics on initial presentation. Future data provided by the NPS may help in the development of recommendations for surveillance guidelines for such patients. This study also provides a framework to address questions regarding the natural history of adenomas and their relationship with colorectal cancer.
We examined data from two large colorectal chemoprevention trials for possible associations of hyperplastic polyps and adenomas with subsequent development of these lesions. Hyperplastic polyps do not predict metachronous adenomas.
The association between rectosigmoid polyps and polyps in the more proximal colon is still a matter of debate, and the need for colonoscopy in patients with rectosigmoid polyps that are detected by flexible sigmoidoscopy is controversial. The aim of this study was to determine whether or not certain characteristics of rectosigmoid polyps are associated with the presence and characteristics of proximal colonic polyps. Seven hundred and twenty-eight patients who underwent total colonoscopy between October 1995 and June 1998 and who had colorectal polyps were retrospectively analyzed. Patients with inflammatory bowel diseases, familial adenomatous polyposis, or any advanced cancer were excluded. The odds ratio (OR) and 95% confidence interval (CI) of prevalence of proximal colonic polyps according to the patients age and sex, as well as the characteristics of rectosigmoid polyps, were calculated. Advanced adenoma was defined as an adenoma larger than 10 mm or an adenoma of any size with villous component, high-grade dysplasia or invasive carcinoma. Among 728 patients with colorectal polyps, 356 patients (48.9%) had polyps only in the rectosigmoid region, 193 patients (26.5%) had polyps only in the proximal colon, and 179 patients (24.6%) had polyps in both the rectosigmoid and proximal colon. In 535 patients with rectosigmoid polyps, the prevalence of proximal colonic polyps, neoplastic polyps and advanced adenomas were 33.4%, 27.3% and 2.9%, respectively. The prevalence of proximal colonic polyps in patients with rectosigmoid polyps was found to be significantly related to the male gender and elderly patients, in addition to the neoplastic histology of the rectosigmoid polyps. However, the prevalence of the proximal colonic polyps was not related to the size, number and shape of rectosigmoid polyps. In 179 patients with both rectosigmoid and proximal colonic polyps, the characteristics of proximal colonic polyps such as size, number and shape were similar to those of rectosigmoid polyps. We recommend total colonoscopic examination in all patients with rectosigmoid adenomas, regardless of the size, number, and shape, especially in elderly males.
Hyperplastic colonic polyps are generally regarded as being of little or no clinical consequence. Recently, however, hyperplastic polyps have been found to share numerous functional similarities with colorectal carcinoma. To determine whether the presence of an isolated left-sided colonic hyperplastic (metaplastic) polyp could serve as a marker for more proximal synchronous adenomatous colonic polyps, we retrospectively analyzed all consecutive colonoscopic polypectomies performed over an 18-month period at two medical centers. It is the policy at both institutions to remove or biopsy all polyps, regardless of size. Indications for colonoscopy included known or previous colonic polyps or carcinoma, hemoccult positive stool, lower gastrointestinal bleeding, iron deficiency anemia, abnormal barium enema, inflammatory bowel disease, abdominal pain, and family history of colon cancer. The location of adenomatous polyps and hyperplastic polyps was recorded and compared. One hundred sixty-three of 845 consecutive patients (19.3%) had at least one colonic polyp. The prevalence of adenomatous polyps alone was 10.3%, hyperplastic polyps 9%, and both types 1.9%. The prevalence rate for an adenomatous polyp in patients without a hyperplastic polyp was 15%. In contrast, among patients with a hyperplastic polyp, 49% had a synchronous adenomatous polyp. Only 3.4% of patients had an adenomatous polyp proximal to the splenic flexure when no polyps were present in the left colon. Conversely, among the 29 patients in whom an isolated hyperplastic polyp was found in the left colon, there was a 32.5% prevalence of adenomatous polyps in the proximal colon (p less than 0.01). The results of this study suggest that left-sided hyperplastic colonic polyps (generally within the reach of a screening sigmoidoscopy) serve as a marker for neoplastic polyps.
An individual's simultaneous nonmalignant gastroduodenal polyps were profoundly spatially clustered in a combined endoscopic and radiographic study of 41 consecutive patients. With endoscopic polyp localization, clustering was demonstrated using a nonparametric test of clustering (Kruskal-Wallis statistic with 40 degrees of freedom = 113.35, probability of observing this extreme statistic with no clustering less than 0.0005) and a parametric test of clustering (F test statistic with 40 and 104 degrees of freedom = 17.05, probability of observing this extreme statistic with no clustering less than 0.0005). In the 26 patients with radiographic polyp localization, polyp clustering was confirmed with the same statistical techniques (e.g., Kruskal-Wallis statistic with 25 degrees of freedom = 88.2, probability of observing this extreme statistic with no clustering less than 0.0005). In patients whose largest polyp was in any given region, there was an increased likelihood that their other polyps would be in that same region. For example, at endoscopy, the nine patients whose largest polyp was in the duodenal bulb had 13 of 15, or 87% +/- 9% (SE), of their other polyps in the duodenal bulb. In contrast, the 11 patients who, at endoscopy, had their largest polyp in the proximal stomach had 2 of 30, or 7% +/- 5% (SE), of their other polyps in the duodenal bulb. Polyp clustering was not dependent on the number of gastroduodenal polyps, or patient age or sex. Patients with at least one hyperplastic polyp, one adenomatous polyp, or with both types of polyps also exhibited profound polyp clustering. These findings suggest that local factors may be important in the pathogenesis of multiple polyps of the stomach and duodenal bulb. In particular, these findings suggest a possibly closer relationship between hyperplastic and adenomatous gastroduodenal polyps than previously appreciated.
OBJECTIVE: Studies of tandem colonoscopies have reported that 15-25% of neoplastic polyps <1 cm in size and 0-6% of larger polyps are overlooked at the time of colonoscopy. We determined the miss rate and "true" 1-yr recurrence of neoplastic polyps in a population of patients reflecting a broad spectrum of different gastroenterology practice settings. METHODS: Patient data from several sources were examined for repeat colonoscopies performed on the same patient within 120 days of each other. Examination pairs were included for analysis if both colonoscopies had good preps and reached the cecum. The miss rate was calculated by two methods: 1) a pooled rate, the total number of polyps on all second examinations divided by the total number on both examinations, and 2) a within-person rate, the average of the individual miss-rates. We estimated a "true" 1-yr recurrence rate by subtracting the proportion of patients with a missed neoplastic polyp from the proportion of patients with a neoplastic polyp found at 1 yr. RESULTS: A total of 76 colonoscopy pairs a mean 47 days apart (range, 1-119 days) were identified from a total of approximately 15,000 examinations and used to calculate the overall miss rates. For the category "all polyps" (neoplastic and nonneoplastic polyps), 17% by the pooled method and 11% by the within-person method were missed. The corresponding rates for neoplastic polyps were 12% by the pooled method and 8% by the within-person method. A total of 17% of patients had one or more neoplastic polyps missed on the initial examination. The observed 1-yr recurrence rate was determined from 1,314 colonoscopy pairs performed a mean of 379 days apart and found to be 28% for neoplastic polyps. By comparing this to the proportion of patients with one or more missed neoplastic polyps, we found the true 1-yr recurrence of neoplastic polyps to be 11%. CONCLUSION: There is a significant colonoscopic miss rate for neoplastic polyps and "all polyps" in clinical practice that is comparable to that previously stated in special research settings. The within-person rate more accurately reflects the true colorectal polyp miss rate for any given colonoscopic exam than does the pooled rate. The difference between the observed 1-yr recurrence rate and the proportion of patients with a missed polyp represents the true 1-yr recurrence of neoplastic polyps.
BACKGROUND/AIMS: Surveillance of individuals with colon polyps is important for the prevention of colon cancer, and its interval is based on the clinical status. Our aims were to determine the recurrence rate of advanced polyp after polypectomy and estimate the adequate interval of surveillance colonoscopy as well as the risk factors of recurrence in Korea. METHODS: Ninety-seven patients who underwent follow-up colonoscopy after initial colonoscopic polypectomy were retrospectively studied. All polyps were endoscopically removed with electrocautery. RESULTS: Mean number of initial polyps were 2.2 and advanced polyps were observed in 40% of the patients. The cumulative recurrence rate of colon polyp was 13.8% within 1 year, and 60% within 3 years, while that of advanced polyps was 2.5% and 31% within 1 and 3 years, respectively. The significant difference was noted according to the initial polyp number in both overall and advanced polyp recurrence rate. The age at the diagnosis of colon polyps was a significant factor only in overall polyp recurrence rate. Patients who initially had one polyp showed 15% of advanced polyp recurrence within 3 years. CONCLUSIONS: Recurrence of advanced polyp is very rare within one year after polypectomy. Patients with single polyp have low risk and thus, their surveillance may be delayed beyond the standard 3 years. When surveillance colonoscopy is to be performed for the patients with 2 or more polyps, initial polyp number and age should be considered.
UNLABELLED: BACKGROUND, AIMS, AND PATIENTS: In a prospective follow up and intervention study of colorectal polyps, leaving all polyps less than 10 mm in situ for three years, analysis of redetection rate, growth, and new polyp formation was carried out in 116 patients undergoing annual colonoscopy. The findings in relation to growth and new polyp formation were applied to 58 subjects who received placebo. RESULTS: Redetection rate varied from 75-90% for each year, and was highest in the rectum and sigmoid colon. There was no net change in size of all polyps in the placebo group, however, polyps less than 5 mm showed a tendency to net growth, and polyps 5-9 mm a tendency to net regression in size, both for adenomas and hyperplastic polyps. This pattern was verified by computerised image analysis. Patients between 50 and 60 years showed evidence of adenoma size increase compared with the older patients, and the same was true for those with multiple adenomas (four to five) compared with those with a single adenoma. The new adenomas were significantly smaller and 71% were located in the right side of the colon. Patients with multiple adenomas had more new polyps at all the follow up examinations than patients with a single adenoma. One patient developed an invasive colorectal carcinoma, which may be evolved from a previously overlooked polyp. Two polyps, showing intramucosal carcinoma after follow up for three years, were completely removed, as judged by endoscopy and histological examination. CONCLUSIONS: The results show that follow up of unresected colorectal polyps up to 9 mm is safe. The consistency of growth retardation of medium sized polyps suggests extended intervals between the endoscopic follow up examinations, but the increased number of new polyps in the proximal colon indicates total colonoscopy as the examination of choice. The growth retardation of the medium sized polyps may partly explain the discrepancy between the prevalence of polyps and the incidence of colorectal cancer.
BACKGROUND: Juvenile polyps, the most common pediatric gastrointestinal polyp, have been typically characterized as either hamartomatous overgrowths or reactive inflammatory proliferations. Recent observations of excessive colonic and gastric carcinoma and dysplasia in juvenile polyposis have prompted reclassification of this entity as a premalignant condition. The relationship between solitary or multiple juvenile polyps and malignancy is less clear. PATIENTS AND METHODS: To further investigate the frequency and significance of dysplasia in juvenile polyps, we analyzed 28 polyps from 21 patients histologically and immunohistochemically for substances previously associated with neoplastic transformation in the colorectal adenomacarcinoma sequence. RESULTS: Fifteen patients had a solitary polyp, two had 2 to 9 polyps, and four had polyposis with 10 or more polyps. Most polyps exhibited inflammatory or regenerative atypia. Foci of dysplasia were noted in polyps from 11 patients, and immunoreactivity for p53 and human chorionic gonadotropin was present in 12 of the 28 polyps each. These findings were all more frequent in the polyposis specimens than in solitary polyps. CONCLUSIONS: These observations, in combination with reports of an increased risk of carcinoma in juvenile polyposis, suggest that juvenile polyps are lesions with a potential for neoplastic and malignant transformation, although they share features of an inflammatory reactive process. The implications for clinical management of patients and pathologic evaluation of juvenile polyps warrant further investigation.
A multicenter, multiyear, case-controlled colonoscopic study of 41 patients with gastric polyps undergoing colonoscopy analyzed whether patients with gastric polyps, particularly adenomas, run an increased risk of having colonic polyps. The primary controls were 109 patients undergoing colonoscopy matched for age and colonoscopy indications. A secondary control group was 69 of these 109 patients who, in addition to matching for age and colonoscopy indications with study patients, had no gastric polyps demonstrated by upper gastrointestinal examination. Patients with nonmalignant mucosal gastric polyps had a significantly greater incidence than primary controls of colonic polyps [odds ratio (OR) = 3.19, OR confidence interval = 1.46 - 6.99, p < 0.004, chi(2)], colonic neoplasms (OR = 3.58, OR confidence interval = 1.56 - 8.23, p < 0.006, chi(2)), and colonic cancer (OR = 4.5, OR confidence interval = 1.05 - 19.4, p < 0.04, Fisher's exact test). Moreover, patients with gastric adenomas had a significantly greater incidence than did primary controls of colonic polyps (OR = 7.6, OR confidence interval = 1.29 - 44.7, p < 0.02, Fisher's exact test). The association between gastric and colonic polyps did not arise as an artifact of the significantly higher frequency of females in the study group because this association remained after patient stratification by sex. The higher risk of colonic polyps in study patients did not arise as an artifact of unappreciated gastric polyps in the primary controls because study patients also had a significantly higher risk of colonic polyps than the secondary controls (OR = 3.21, OR confidence interval = 1.35 - 7.63, p , 0.01, chi(2). Our retrospective case-controlled study suggests that gastric adenomas may be a new, significant risk factor for colonic polyps. A strong association would require that patients with gastric adenomas undergo surveillance colonoscopy to diagnose and remove colonic polyps. However, before we apply this finding to clinical practice, the apparent association should be confirmed by another, preferably prospective study.
In an endoscopic population screening study for colorectal polyps among 200 men and 200 women, 50-59 years of age, 215 polyps less than 5 mm in diameter were left in situ for the present 2-year follow-up examination. The attendance rate was 102 of 106 (96%) for polyp patients and 77 of 90 (86%) in the control group. Of 194 polyps, 143 (74%) in the 102 polyp-bearing individuals were recovered for histological evaluation and 57 polyps were registered as new. Ninety-nine (50%) of the polyps were hyperplastic, 45 (23%) were adenomas, and 45 (23%) were mucosal tags. Both growth and regression of polyps were registered. Regression was commoner in the distal part of the rectum than in the proximal part or distal sigmoid colon. Growth was similar for recovered adenomas and hyperplastic polyps, whereas mucosal tags more often showed diminution in size. No polyp had reached a size of more than 5 mm in 2 years, and no case of severe dysplasia or carcinoma was registered. The estimated total polyp mass more than doubled both for adenomas and hyperplastic polyps. It is concluded that the time interval between initial examination with removal of polyps 5 mm or larger in diameter and the first follow-up examination may safely be set at 2 years.
We performed a retrospective review of 477 cases of fundic gland polyps compared with 562 cases of hyperplastic polyps, which were detected endoscopically during the past 8 years between January, 1989 and December, 1996. All lesions were histologically confirmed by endoscopic biopsy or the examination of polypectomy specimens. Fundic gland polyps were more prevalent in middle aged-female, and were not associated with gastric adenomas and gastric cancers. These results suggested that the background mucosa of patients with fundic gland polyp was different from that of patients with hyperplastic polyp. Fundic gland polyps in 55 patients were followed up. No change was observed in the polyps of the about half subjects, the polyps of 12 cases (21.8%) decreased in size and number or resolved completely. Cases decreased in size and number or resolved completely were much more in fundic gland polyps than hyperplastic polyps. There were no malignant transformation of fundic gland polyps. We claimed that fundic gland polyps were benign and distinct from hyperplastic polyps which had a possibility of malignant transformation.
OBJECTIVES: to compare morphological and clinical features of antrochoanal polyps and chronic inflammation-associated polyps of the maxillary sinus. STUDY DESIGN: histological and scanning electron microscopic examination of ten antrochoanal polyps and ten chronic inflammation-associated polyps of the maxillary sinus; comparison of clinical data in both groups of patients. METHODS: following surgical removal, the polyps were halved, the halves being processed for routine light microscopy (formalin fixation, paraffin embedding, HE staining) and scanning electron microscopy (formaldehyde/glutaraldehyde fixation, critical point drying, gold coating), respectively. Clinical data were retrospectively reviewed, tabulated and compared. RESULTS: the antrochoanal polyps differed from chronic inflammation-associated polyps of the maxillary sinus only in a few minor features; slightly longer duration of the process, lower incidence of maxillary ostial obstruction, higher incidence of frequent headaches, persistent nasal obstruction, presence of cysts in the polyp stroma, thickened basement membrane, lower incidence of squamous cell metaplasia, and higher proportion of migratory cells in nasal smears. In two cases, allergy was diagnosed but it seemed not to influence the polyps, which did not show morphological features typical of allergy-associated (eosinophilic) polyps. CONCLUSIONS: In spite of minor differences, antrochoanal polyps can be regarded as chronic inflammation-associated polyps with cystic origin and peculiar localization.
AIM: To investigate the distribution of DNA microsatellite instability (MSI) in a series of hyperplastic polyps, serrated adenomas, and mixed polyps of the colorectum. METHODS: DNA was extracted from samples of 73 colorectal polyps comprising tubular adenomas (23), hyperplastic polyps (21), serrated adenomas (17), and mixed polyps (12). The presence of MSI was investigated at six loci: MYCL, D2S123, F13B, BAT-40, BAT-26, and c-myb T22, using polymerase chain reaction based methodology. MSI cases were classified as MSI-Low (MSI-L) and MSI-High (MSI-H), based on the number of affected loci. RESULTS: The frequency of MSI increased in tubular adenomas (13%), hyperplastic polyps (29%), serrated adenomas (53%), and mixed polyps (83%) (Wilcoxon rank sum statistic, p < 0.001). Hyperplastic epithelium was present in nine of 12 mixed polyps and showed MSI in eight of these. MSI was mostly MSI-L. MSI-H occurred in two serrated adenomas and three mixed polyps. Clonal relations were demonstrated between hyperplastic and dysplastic epithelium in four of eight informative mixed polyps. CONCLUSIONS: The findings support the view that hyperplastic polyps may be fundamentally neoplastic rather than hyperplastic. A proportion of hyperplastic polyps may serve as a precursor of a subset (10%) of colorectal cancers showing the MSI-L phenotype, albeit through the intermediate step of serrated dysplasia. This represents a novel and distinct morphogenetic pathway for colorectal cancer.
A case-control study was conducted searching through 590 diagnostic hysteroscopies in order to identify potential risk factors for endometrial polyps. Case (hysteroscopically positive for endometrial polyps) and control groups were compared for age, parity, cervical polyp, menopausal status, smoking and current use of contraceptive pills. A higher prevalence of endometrial polyps was found among women with a cervical polyp (26.9%) compared to those without a cervical polyp (7.1%, chi(2) = 27.52, p < 0.001). Increased risk of endometrial polyp was found to be associated with age (odds ratio = 1.75 every 10 years, p < 0.001), cervical polyp (odds ratio = 4.83, 95% CI = 2.43-9.52), and menopause (odds ratio = 2.03, 95% CI = 1.12-3.69). After multivariate analysis, only age (adjusted odds ratio = 1.90, p = 0.001) and cervical polyp (adjusted odds ratio = 5.42, p < 0.001) were independent variables still associated with increased risk of endometrial polyps. We conclude that age and cervical polyp are strong, independent risk factors for endometrial polyps.
The pathogenesis of juvenile polyps of the colon was studied in a patient with multiple juvenile polyposis who underwent proctocolectomy for rectal carcinoma and antrectomy for associated polyps of the stomach. Numerous polyps up to 3 cm in diameter were present predominantly in the cecum and rectum, and in addition there was an adenocarcinoma in the rectum. Microscopically there were five categories of lesions: 1) Hyperplastic epithelial foci and small hyperplastic polyps; 2) Typical Juvenile polyps; 3) Juvenile polyps with focal adenomatous epithelium; 4) Adenomas; and 5) and adenocarcinoma. The five categories could represent a pathogenetic sequence, beginning with epithelial hyperplasia, leading to small hyperplastic polyps which become inflamed and enlarge, forming juvenile polyps. Focal adenomatous areas which develop in some juvenile polyps might give rise to adenomas and in turn lead to carcinoma. Although juvenile polyps are generally not considered to be premalignant lesions, this case demonstrates that neoplastic changes may occur in juvenile polyps in certain individuals, and raises the possibility that these may on occasion give rise to carcinoma.