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Prevalence and malignant potential of colorectal polyps in asymptomatic, average-risk men.

Screening colonoscopy was performed on 119 asymptomatic elderly men with no other risk factors for colonic neoplasms. Ninety adenomas were detected in 49 (41%) subjects. Mean adenoma size was 6.5 mm, with 83 (92%) less than or equal to 10 mm. Forty-nine (54%) adenomas were located proximal to the splenic flexure, and 17 (19%) were classified as tubulovillous or villous. Moderate- to high-grade dysplasia was found in 29 (32%) adenomas and was associated with larger size (p less than 0.0001) and villous architecture (p = 0.0038). Two subjects harbored adenomas with invasive cancer. Seventy-one hyperplastic polyps were found in 40 (34%) subjects. The mean size of hyperplastic polyps was 3.4 mm, and 64 (90%) were located in the left colon. We conclude that, in this population, adenomas are common lesions that are frequently small. However, substantial proportions of these adenomas may be at risk for malignant degeneration due to the presence of villous architecture and higher grades of dysplasia. Because adenomas and hyperplastic polyps are endoscopically indistinguishable, all polyps found at endoscopy should be removed or ablated.

Aged↗

Antro-choanal polyp: a 10-year retrospective study in the pediatric population with a review of the literature.

Antro-choanal polyp is generally recognized to represent approximately 4-6% of all nasal polyps; however, it is much more prevalent in the pediatric population. It warrants special consideration in children because its clinical manifestations may be mimicked by other less benign conditions, such as juvenile angiofibroma, meningoencephalocele, and nasopharyngeal malignancies. Fifty patients with surgically treated nasal polyps were reviewed at the Montreal Children's Hospital, between 1976 and 1986. Fourteen (28%) were antro-choanal polyps. Our results are compared with the literature, and special emphasis was given to radiographic manifestations and the differential diagnoses.

Adolescent↗

A clinical and histopathological study of gastric polyps in familial polyposis coli.

Fundic gland area gastric polyps in familial polyposis coli (FPC) were compared with those in non-familial polyposis coli clinicopathologically to elucidate their histogenetic and biological characteristics. Some differences were observed in age, sex, and radiological and endoscopical features. Although the polyps were similar histologically, they showed an apparent histochemical difference between the two groups in periodic borohydride technique/potassium hydroxide/periodic acid-Schiff stain which demonstrates O-acylated sialic acid. The superficial and foveolar epithelium of the polyps was positive in 10 of 12 familial polyposis coli cases, while the epithelium was positive in only one of 13 non-familial polyposis coli cases with the same staining. These results suggest differences between the two groups in the degree of epithelial intestinal metaplasia. The presence of gastric polyps with O-acylated sialic acid therefore indicates the necessity of examination of the colorectum.

Adolescent↗

[Colonic polyps. Experience at a clinical center in Caracas].

After six years experience in the anatomopathological study and having checked 33.452 histological cases 772 corresponded to colon tumoral pathology. It was then decided to proceed with the epidemiological analysis of the polyps, it's anatomical distribution according to sex and age, it's histolopathological characteristics and the possible relationship with malignant transformation. We found a clear predominance mainly of adenomatosic neoplasic polyps, followed by hyperplasic polyps. 65% of the patients were male and more than half of the cases were between the ages of 50 and 70. Coincitentally, 86% of the atypical polyps were found within this age group.

Adenoma, Villous↗

[Therapeutic colonoscopy in patients with colonic and rectal polyps].

598 colorectal polyps were removed by therapeutic colonoscopy from 377 patients, of both sexes, between 1 and 88 years old, most of them with lower digestive symptoms. The polyps were unique in 67.37% and multiple in 32.63% of patients, and mostly located in rectum and sigmoid colon; 42.14% were pedunculated, 33.95% sessile++/sub-pedunculated, and 23.91% sessile in shape. In 51% the size was over 10 mm in diameter. Histologically, 68.68% were of epithelial neoplastic type: 60.91% adenoma; 6.42% adenoma with adenocarcinoma, and 1.35% polypoid carcinoma. 30.64 were epithelial non-neoplastic type: 20.32% hyperplastic polyp, and 0.51% hyperplastic polyp with tubular adenoma. Two patients (0.53%) had lower digestive hemorrhage immediately after the polypectomy. The complications were controlled with conservative measures without blood transfusion.

Adolescent↗

Risk of proximal colon neoplasia with distal hyperplastic polyps: a meta-analysis.

BACKGROUND: Most guidelines for colorectal cancer screening do not consider distal hyperplastic polyps (HPs) to be markers for proximal colon neoplasia. However, many studies have shown an increased risk of proximal neoplasia (PN) in patients with distal HPs. We performed a systematic review to assess the association between distal HPs and PN. METHODS: We identified studies that compared the prevalence of PN and proximal advanced neoplasia in patients with distal HPs vs controls. Two masked investigators extracted data on individuals with distal HPs, distal adenomas, or no distal polyps. Using the DerSimonian and Laird method, we calculated summary risk ratios. Extensive subgroup analysis was performed. RESULTS: The prevalence of PN and proximal advanced neoplasia in persons with distal HPs was 26.0% and 4.4%, respectively. In studies comparing the risk of PN in patients with distal HPs vs those with no distal polyps, the summary risk ratio was 1.81 (95% confidence interval, 1.20-2.73). However, this increased risk disappeared if only high-quality studies on screening patients were considered. The risk ratio was 0.69 (95% confidence interval, 0.60-0.80) when comparing the risk of PN in those with distal HPs vs those with distal adenomas. CONCLUSIONS: Overall, patients with distal HPs have an intermediate risk of PN compared with those with distal adenomas or no distal polyps; however, in asymptomatic screening individuals, there is no increased risk of PN or proximal advanced neoplasia. The discovery of HPs on screening flexible sigmoidoscopy should not automatically prompt follow-up colonoscopy.

Adenoma↗

Inflammatory bronchial polyps associated with asthma.

We report a case of inflammatory bronchial polyps associated with asthma in a 10-year-old boy. He expelled about 50 polyps varying in size from 0.4 to 1.8 cm without difficulty. Microscopically, the polyps were lined by columnar epithelium supported by stroma consisting of a loose connective tissue with many capillary vessels and a chronic inflammatory infiltration composed mainly of lymphocytes, plasma cells, and eosinophils. The blood and urine laboratory data were normal except for blood eosinophilia of 3% to 10%, and a chest roentgenogram that showed a left perihilar small nodular lesion and a small irregular area in the right upper lobe. Test results of pulmonary function and blood gases were normal. The association of bronchial inflammatory polyps with asthma and the clinical manifestation in this patient is very uncommon.

Asthma↗

Expression of cyclooxygenase and lipoxygenase enzymes in nasal polyps of aspirin-sensitive and aspirin-tolerant patients.

OBJECTIVE: To evaluate the expression of cyclooxygenase (COX) and lipoxygenase (LO) enzymes in nasal polyp specimens from aspirin-sensitive (AS) and aspirin-tolerant (AT) patients. DESIGN: Immunohistochemical staining of archived tissue. Subjects Specimens from 26 patients (11 AS and 15 AT) with nasal polyps were analyzed; specimens from 4 patients were used as controls. INTERVENTIONS: Immunohistochemical techniques were used to evaluate the expression of the enzymes COX-1, COX-2, 5-LO, 12-LO, and 15-LO in nasal polyp tissue specimens from AS and AT patients. The results were compared with those of a control group of patients without a history of nasal polyposis or rhinosinusitis. RESULTS: Characteristic staining patterns of epithelium and submucosal glands were noted for each enzyme. Statistically significant (P<.05) differences in staining of columnar epithelium were noted for COX-1 (basal cell layer cytoplasm), COX-2 (apical cell layer cytoplasm), and 12-LO (full-thickness cytoplasm and nucleus). Increased 15-LO (full-thickness cytoplasm) expression in columnar epithelium was noted only in the AT group. Significant differences in the staining of submucosal glands were noted for COX-2 (plasma membrane and cytoplasm), 12-LO (cytoplasm), and 15-LO (cytoplasm) between control and AS patients as well as between control and AT patients (P<.05). The only significant difference noted between the AS and AT groups was cytoplasm staining for 5-LO in submucosal glands, which was greater in the AS group. No epithelial staining differences were noted between AT and AS patients. CONCLUSIONS: There were significant differences in the expression of COX and LO enzymes between patients with nasal polyps and controls, irrespective of aspirin sensitivity. With 1 exception, there were no significant differences between AS and AT groups.

Anti-Inflammatory Agents, Non-Steroidal↗

Mucous glands in nasal polyps.

A total of 102 nasal polyps from 52 patients were stained by the PAS-alcian blue whole-mount method, and mucous glands were studied quantitatively. Glands were found in all polyps but in many of them only a few. The density is very low, considerably lower than in the nasal mucosa. The glands are tubular, of different shape and size, but differ widely from those in the nose and are formed from the surface epithelium after the polyp has attained a certain size. They do not issue from the nasal mucosa. The glands degenerate and distend. Thus, cysts in the polyp are degenerated, mucus-filled glands.

Adolescent↗

Malignant transformation of nasal polyp. Case report.

Malignant transformation of nasal polyps is believed to be very rare. A 49-year-old man had suffered from nasal polyposis and visited the hospital complaining of nasal obstruction and a huge nasal polyp in the right nostril. Histologic findings showed squamous cell carcinoma with microinvasion on the surface of the polyp and no invasion of carcinoma in the stalk. Simultaneously, malignant transformation of a small polyp was found in the left nasal cavity. Clinical and histologic findings are discussed.

Carcinoma, Squamous Cell↗

Insulinlike growth factor I immunoreactivity in nasal polyps.

Nasal polyps from 15 patients were all found to express increased insulinlike growth factor I immunoreactivity. A hypothesis for the formation of nasal polyps is described: macrophages, seen in allergic and infectious reactions, produce and release growth factors, tentatively including insulinlike growth factor I. In enclosed paranasal sinuses this results in an accumulation of insulinlike growth factor I stimulating the growth of both epithelium and blood vessels in the sinuses. The mucosa increasingly bulges out through the ostium after having filled out the sinusity. Continuing growth stimulation is supplied by the inflammatory reaction, endothelial cells in the polyp, and activated macrophages inside or outside the polyp.

Adolescent↗

A truncated poisson regression model with applications to occurrence of adenomatous polyps.

Adenomatous polyps are considered as the dominant precursor lesion of colorectal cancer. A phase III colorectal cancer prevention trial, conducted by the Arizona Cancer Center, concerns the ability of wheat bran fibre supplement to reduce the recurrence of adenomatous polyps. All participants in the study are to have had colorectal polyps detected and removed during a baseline (qualifying) colonoscopy within three months prior to enrolment. In this paper, our interest focuses on occurrence of adenomatous polyps at the baseline colonoscopy. We use a truncated Poisson model to fit these types of data. We develop a regression model to assess the effects of explanatory factors on the positive counting variable. We fit truncated Poisson parameters by a log-linear regression model and estimate regression parameters by the maximum likelihood procedure. Finally, we apply it to the baseline colonoscopy data from the Wheat Bran Fiber study.

Adenomatous Polyps↗

The epidemiology of colorectal polyps: prevalence in New Orleans and international comparisons.

Based on a study of the prevalence of intestinal polyps in New Orleans and on international comparisons, the following conclusions are reached. 1) There is a close parallelism in the epidemiology of colon cancer and adenomatous polyps. Both conditions are statistically associated with respect to geography, anatomic localization, socioeconomic class, migration experience and time trends. 2) The strength of the association favors the notion of a direct, positive correlation between multiplicity, size and atypia of polyps, and cancer risk, equivalent to "dose-effect". 3) The epidemiologic findings are coherent with other biologic facts derived from clinical, morphological and experimental studies. 4) Adenomatous polyps are a good epidemiologic indicator of colon cancer risk and their presence should be helpful in advancing from studies of the epidemiology of colon cancer to the epidemiology of precursor lesions.

Adult↗

The histopathology of bleeding from polyps and carcinomas of the large intestine.

Carcinomas, adenomas and nonneoplastic polyps of the large intestine were examined histopathologically for evidence of recent and old hemorrhage. Three percent of the carcinomas lacked evidence of hemorrhage, as did 7% of the adenomas. Fifty percent of hyperplastic polyps were negative for hemorrhage, but 23% had considerable hemorrhage or hemosiderin. These findings may have a bearing on the results in fecal occult blood testing for the detection of cancer. Carcinomas bleed mainly from erosions on their luminal surface, but adenomas rarely show this feature. Twisting and bending of polyps, leading to fracture of fronds, and vascular obstruction, with passive congestion and stromal hemorrhage, appear to be the main sources of bleeding in polyps. Adenomas on the left side of the large intestine showed greater evidence of bleeding than did lesions on the right, but carcinomas did not show this relationship. Factors correlated with more severe hemorrhage were size, pedunculation, and villous growth of adenomas; for carcinomas, they were size, lack of mucin content, and lower differentiation. The age and sex of the patient and the extent of spread of carcinomas did not correlate with hemorrhage.

Adenoma↗

Recurrence rates for colorectal polyps.

Of 276 patients who underwent an initial colonoscopic polypectomy for adenomatous polyps over a 45-month period, 118 subsequently had one or more repeat screening colonoscopies. The mean follow-up time was 26 months with an overall polyp recurrence rate of 30%. Analysis of these data retrospectively suggests that the bulk of the recurrences occurred within the first year. Increasing age was found to be a significant risk factor for polyp recurrence. Asymptomatic recurrence of adenomatous polyps detectable by colonoscopy is a common occurrence in postpolypectomy patients. Prospective studies utilizing colonoscopy as a screening tool are needed to establish a rational screening policy for this high-risk group.

Colonic Diseases↗

Study of the cell proliferation kinetics in ulcerative colitis, adenomatous polyps, and cancer.

Cell proliferation kinetics, using autoradiography, was investigated in 4 specimens of normal colonic mucosa, 11 cases of ulcerative colitis, 15 adenomas, and 17 advanced cancers of the large intestine. In the normal mucosa, the labeled cells were located only in the lower three fifths of the crypts, the so-called proliferation zone, and their labeling index was 11.7 +/- 4.0%. In the ulcerative colitis, the proliferation zones were remarkably extended toward the upper part of the crypts, and the mean labeling index was 20.5 +/- 9.4%. In the adenomatous polyps, labeling was seen in any part of the crypts, and abnormal proliferation patterns such as denseness, stratification, expansion, and budding of the labeled cells tended to increase in accordance with the degree of the histologic atypism. Their mean labeling index was 22.2 +/- 8.6%. However each labeling index of the polyps increased proportionally to their histologic atypism, from 15.2 +/- 8.1% in grade II to 30.1 +/- 9.9% in grade V. The mean labeling index of the cancers was 23.3 +/- 9.6%, and there was little difference in the labeling patterns of the malignant polyps and cancers. The proliferation patterns of the polyp and cancer were qualitatively different from those of the normal mucosa and the ulcerative colitis.

Autoradiography↗

The care of patients with colorectal polyps that contain invasive adenocarcinoma. Endoscopic polypectomy or colectomy?

BACKGROUND: The appropriateness of resection in patients from whom polyps with invasive adenocarcinoma were excised has been questioned. METHODS: To determine the results of this policy, the authors reviewed the outcome of 42 patients from whom 44 such polyps were removed. Each polyp was categorized for the level of invasion according to the classification of Haggitt. RESULTS: Level 1 invasion was found in 27%; level 2, in 9%; level 3, in 11%; level 4, in 39%; and uncertain, in 14%. The histologic grade was well differentiated in 48% of patients and moderately differentiated in 52%. No polyps contained poorly differentiated adenocarcinoma; lymphatic and vascular invasion were not encountered. Excision was judged complete in 23 patients; 11 underwent resection, and in none was residual adenocarcinoma identified. In 14 patients, margins could not be evaluated; of 12 patients who underwent resection, residual adenocarcinoma was found in 1. Of the seven patients with positive margins who underwent resection, residual adenocarcinoma was found in only two. In the resected specimens in which residual carcinoma was encountered, all original lesions were designated level 4. None of the patients treated by polypectomy alone has experienced a recurrence at a mean follow-up time of 66 months (range, 12-152 months). CONCLUSIONS: The authors conclude that only patients with level 4 invasion require resection.

Adenocarcinoma↗

Aspirin use, cancer, and polyps of the large bowel.

BACKGROUND: The effect of aspirin use on 490 patients with cancer of the colon, 340 with cancer of the rectum as the first primary site, and 212 patients with polyps having no coexisting malignancies was compared with that of two groups of control subjects that consisted of 524 hospital patients having no cancers and no diseases of the digestive organs and 1138 healthy visitors to the screening clinic. All subjects entered Roswell Park Cancer Institute between 1982 and 1991. METHODS: After adjustment for adulthood lifetime duration of aspirin use, sex, age, residence, and education, the risk of having cancers and polyps of the colon or the rectum among people who had been using aspirin at least for 1 year before the illness relative to that of nonusers was estimated using multiple logistic regression procedure. RESULTS: The odds ratio estimates showed that the risk of colorectal cancers declined progressively as the frequency of aspirin use increased compared with control groups. Among patients reporting use of aspirin two or more times a day, the odds ratio estimates for colorectal cancers were 0.33 (95% confidence interval [CI], 0.72-0.15) and 0.44 (95% CI, 1.10-0.18) compared with those of screening clinic visitors and hospital control subjects, respectively. The odds ratio for patients with polyps who had used aspirin less than once a day relative to that of nonusers was 0.28 (95% CI, 0.62-0.13) and 0.43 (95% CI, 1.09-0.17) compared with screening clinic visitors and hospital control subjects, respectively. CONCLUSIONS: There is a risk reduction effect of aspirin use on the incidence of colorectal cancers and polyps, and this effect is dose related.

Aspirin↗