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PubMed1998

Juvenile polyp in esophageal colon interposition.

Esophageal polyps are rare in children, whereas colorectal juvenile polyps are common. An 11-year-old boy with an esophageal colonic interposition for an esophageal stricture secondary to caustic injury was found to have a polypoid mass in the interposed colon. Fiberoptic endoscopic removal with diathermy was performed. Histological examination confirmed it was a juvenile polyp. The occurrence of a polyp in a colon removed from its natural location and serving a different function suggests the possibility that an unknown factor produced by colonic cells play a pivotal role in its development.

Burns, Chemical↗
PubMed1991

Colonic fermentation of dietary fibre to short chain fatty acids in patients with adenomatous polyps and colonic cancer.

Short chain (C2-C6) fatty acids are produced in the colon through bacterial fermentation of mainly dietary fibre. Butyrate (C4) possesses antineoplastic effects on human colon carcinoma cells, and epidemiological studies indicate that high fibre diets may reduce the incidence of colorectal cancer. The role of dietary fibre during colorectal carcinogenesis might therefore be related to its fermentation to butyrate. Faecal concentrations of total short chain fatty acids and concentrations and ratios of the individual C2-C6 fatty acids did not differ between 16 healthy controls, 17 patients with colonic adenomas, and 17 patients with colonic cancer. Comparison of the molar production velocities (mmol/l.hour) of total and individual short chain fatty acids from glucose, ispagula, wheat bran, and albumin in six and 24 hour faecal incubations showed no differences. The ratio of butyrate production to total short chain fatty acid production from fibre, however, was reduced in patients with colonic cancer and adenomas compared with healthy controls (ispagula, six hours: 6.4, 7.6, and 11.5% respectively, p = 0.005 and 24 hour: 9.1, 9.9, and 15.4%, p = 0.002; wheat bran, six hours: 9.9, 10.2, and 14.7% respectively, p = 0.06 and 24 hours: 15.1, 16.8, and 21.0%, p = 0.01). It may be that the low ratios of colonic butyrate formation combined with low fibre diets increase the risk of colonic neoplasia.

Adenoma↗
PubMed1981

Diagnostic and therapeutic colonoscopy - a review of 300 examinations.

In a period of twenty-two months, 300 patients were subjected to colonoscopic examinations. The proximal colon could be intubated in more than 90% of patients, when there was no distal obstruction or contraindications. Colonoscopy provided a more accurate diagnosis of colorectal diseases when correlated with barium enema examinations, and several unnecessary operations were thus avoided. However both procedures should be regarded as complementary rather than competitive. Colonoscopic polypectomy has revolutionised the management of colonic polyps, which are precursors to most colonic carcinomas. It has greatly reduced the need for laparotomy and surgical polypectomy. The morbidity, mortality, length of hospitalization and cost are significantly lower with colonoscopic polypectomy when compared with surgical polypectomy. In the present series, 45 colonic polyps were removed from 32 patients without any complications. The increased use of colonoscopic polypectomy may reduce the death rate from colonic carcinoma.

Adolescent↗
PubMed1985

Ploidy studies in adenomatous polyps of the colon.

The nuclei of colonic adenomatous polyps and some colonic carcinomas have a normal diploid profile. The remaining carcinomas are aneuploid, and this change most probably occurs after the dysplasia that determines invasiveness, because even adenomatous polyps with carcinoma in situ are diploid.

Adenocarcinoma↗
PubMed2005

Do forceps biopsies truthfully reflect the nature of endoscopically uncovered polypoid lesions of the colon?

BACKGROUND: Total excision of colonic polyps is not always attainable and in some patients it is clinically contraindicated. Also, a resected polyp may be lost at any step between its endoscopic removal and its embedding in paraffin. The aim of this study was to compare the histological features of colonic polyps as analysed by the study of biopsy-forceps obtained samples with those assessed on scrutinizing the totally resected growths. PATIENTS AND METHODS: This prospective study included a cohort of 59 patients in whom, in the course of an elective colonoscopy, a total excision of a 6 mm-sized or larger polyp was called for. Sizeable biopsies were obtained by means of an Olympus Multibyte forceps prior to the total polypectomy. Subsequent to the study of the polypectomy specimens, the forceps biopsy samples were submitted for histological examination. The pathologists were blinded as to the source of the tissue they were studying. The diagnoses rendered by evaluating the biopsy samples and polypectomy specimens of each patient were contrasted with each other. RESULTS: Major discrepancies between the histological features of the fragments captured by the biopsy-forceps and the factual nature of the totally removed polyps were uncovered in 11 (18.6%) of 59 cases. Intriguingly, the grade of the tumours was underrated in all the 11 cases, as judged by contrasting the tentative diagnoses of the forceps-biopsies with the decisive diagnoses of the polypectomies. Importantly, 2 adenocarcinomas would have been missed by just looking at the forceps-retrieved sample. CONCLUSIONS: In our experience, a discordance of 18.6% is to be expected between the diagnoses rendered after examining forceps-biopsies of and totally excised colonic polyps. Nevertheless, it is advisable to procure biopsies prior to the excision of the growths, because on those occasions in which patients' growths cannot be removed or have not been retrieved for one reason or another, a small forceps-captured tissue sample correctly reflects the characteristics of the polyp in 81.4% of the cases. Finally, the biopsies may be discarded in the event that total removal was successful.

Adult↗
PubMed2000

Automated polyp detector for CT colonography: feasibility study.

An abdominal computed tomographic scan was modified by inserting 10 simulated colonic polyps with use of methods that closely mimic the attenuation, noise, and polyp-colon wall interface of naturally occurring polyps. A shape-based polyp detector successfully located six of the 10 polyps. When settings that enhanced the edge profile of polyps were chosen, eight of 10 polyps were detected. There were no false-positive detections. Shape analysis is technically feasible and is a promising approach to automated polyp detection.

Colon↗
PubMed2001

Hyperplastic polyp with epithelial misplacement (inverted hyperplastic polyp): a clinicopathologic and immunohistochemical study of 19 cases.

Hyperplastic polyps of the colon are the most common type of benign colonic polyp. Rarely, these polyps may show misplaced epithelium within the submucosa, thereby simulating an adenoma with pseudoinvasion or even an adenocarcinoma. In this study, we describe the clinical, pathologic, and immunophenotypic features of 19 hyperplastic polyps with misplaced epithelium to identify potential diagnostic pitfalls and gain insight into their pathogenesis. Routinely processed polypectomy specimens from 12 patients with 19 hyperplastic polyps containing foci of misplaced epithelium were evaluated for a variety of morphologic features including pattern and extent of submucosal involvement, continuity of the submucosal epithelium with the mucosa, presence of recent or remote hemorrhage, inflammation, association of misplaced epithelium with lymphoid aggregates, inflammation, and defects in the muscularis mucosae. Clinical and endoscopic data were obtained and correlated with the histologic findings. Immunoperoxidase stains (ABC method) for collagen IV (basement membrane marker), MIB-1 (proliferation marker), and E-cadherin (intercellular adhesion protein) were performed in all cases. The study group consisted of five males and seven females ranging in age from to 52 to 73 years (mean: 63 y). All of the polyps were located in the rectum or sigmoid colon, and their mean size was 0.5 cm (range: 0.2 to 1.0 cm). Most showed misplaced epithelium in a lobular (26%) or a mixed pattern consisting of lobules and irregularly distributed crypts (63%) that, upon deeper levels, was almost always continuous with the mucosal portion of the polyps (95%). Defects in the muscularis mucosae and splaying of the muscle fibers around misplaced epithelium were seen in all cases. Lymphoid aggregates were present adjacent to foci of misplaced epithelium in 37% of cases. Fresh hemorrhage, vascular congestion, and hemosiderin deposits were present in 79, 53, and 42% of cases, respectively. Strong and uniform staining of the misplaced epithelium for MIB-1 and E-cadherin was demonstrated in all cases, similar to that seen in the lower third of the mucosal portion of the polyps. A continuous collagen IV basement membrane pattern of staining was noted around all foci of misplaced epithelium. Hyperplastic polyps with misplaced epithelium probably occur secondary to trauma-induced protrusion of glands through breaks in the muscularis mucosae. Pathologists should be aware of this entity to avoid diagnostic confusion with other, more serious lesions, such as adenomas with pseudoinvasion or well-differentiated adenocarcinoma.

Aged↗
PubMed1995

A review of gastrointestinal epithelial renewal and its relevance to the development of adenocarcinomas of the gastrointestinal tract.

Renewal of the gastrointestinal (GI) epithelium fulfills the normal functions of maintaining the integrity of the mucosa, repairing mucosal injury, and replenishing the specialized cells of the epithelium. Alterations in epithelial renewal also are intimately involved in transformation of the epithelium to benign and malignant neoplasms. Certain abnormalities in epithelial proliferation, including an increase in the rate of proliferation and expansion of proliferating cells beyond the normal zone of proliferation, are closely linked to the predisposition for and frank development of GI cancer. These abnormalities are common to all human premalignant conditions studied, including Barrett's epithelium, chronic gastritis, inflammatory bowel disease, and colon polyps; they also occur in experimental carcinogenesis. The same proliferative abnormalities have also been observed in some relatives of patients with colon neoplasms who themselves do not have any colon polyps or cancer. Several agents, including calcium, vitamins A, C, and E, and omega-3 fatty acids, have been shown to reverse the abnormal proliferation under some laboratory and clinical conditions. Moreover, some nonsteroidal anti-inflammatory drugs appear to decrease the size of colon polyps in familial polyposis and to reduce the risk for colon cancer in the general population. We await further clinical trials that will indicate whether such ordinary supplements as calcium, vitamins, fish oil, or aspirin have a role in the treatment of patients with premalignant conditions of the gastrointestinal tract.

Adenocarcinoma↗
PubMed1988

A case of generalized juvenile gastrointestinal polyposis associated with gastric carcinoma.

A case of generalized juvenile gastrointestinal polyposis associated with gastric adenocarcinoma is described. A 31-year-old male patient developed polyposis of the stomach complicated by gastric carcinoma and multiple polyps in the colon. Polyps of the stomach and colon were pathologically consistent with juvenile polyp, but adenomatous changes were also present in a very small percentage of the juvenile polyps. This case strongly suggests the possibility of carcinoma developing in patients with generalized juvenile gastrointestinal polyposis.

Adenocarcinoma↗
PubMed2005

Karyometry in rectal mucosa of patients with previous colorectal adenomas.

OBJECTIVE: To determine whether karyometric measurements taken in biopsies from histologically normal-appearing rectal mucosa could serve as a biomarker for the risk of recurrence of polyps. MATERIALS AND METHODS: Biopsies were taken from the rectal mucosa of cases with a prior history of colonic polyps at the baseline of the study. In 57 cases recurrent polyps occurred (R cases); in 72 cases no recurrent disease was found at the end of the study (NR cases). From each biopsy 100 nuclei were recorded at high resolution. After segmentation, feature extraction and selection of a discriminating subset of features, a number of discriminant functions were derived. Also, measures of nuclear abnormality were computed. RESULTS: The differences in karyometricfeature values for nuclei from biopsies of cases with recurrent or nonrecurrent disease were very small and not notably expressed in the majority of nuclei. It was possible by focusing on nuclei showing clear deviations from normal to derive a discriminant function that exhibited a shift for the NR and R data sets. The distributions of discriminant function scores were then subjected to a second-order discriminant analysis to separate cases according to recurrence status. This function showed a statistically highly significant correlation with recurrence. At one extreme of its score distribution were 11 of 57 cases that had a recurrence, and at the other extreme were 8-10 of 72 cases that had no recurrence. The distributions of nuclear abnormality values for these subsets of cases were drastically different, with an average value of 1.72 for the group that may be at high risk for another recurrence and 1.02 for the group possibly at low risk. All cases with a prior history of colonic polyps showed a nuclear abnormality deviating from normal. CONCLUSION: Measurement of a sample of 100 nuclei from the rectal mucosa will suggest, for approximately 10% of cases, that a high risk for recurrence of adenomatous polyps exists and, for a slightly lower proportion, confirm that the nuclei deviate only slightly from those from individuals with no history of colonic polyps. For the majority of cases with a prior history of adenoma, the nuclei in the biopsy show a notable deviation from normal, but the deviation is practically the same for cases that had a recurrence and those that did not. However, a tentative discriminant function (DF I,3) derived from the characteristics of the extreme cases correctly classified approximately 64% of nonrecurrent and 83% of recurrent cases using a Bayesian decision boundary.

Adenomatous Polyposis Coli↗
PubMed1991

Carcinoembryonic antigen has a different molecular weight in normal colon and in cancer cells due to N-glycosylation differences.

Carcinoembryonic antigen, an apical membrane glycoprotein expressed in normal human colonic epithelial cells, colonic polyps, tumor, and tissue culture cell lines originating from colonic adenocarcinomas, is generally considered to have a molecular weight of 180,000. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis associated with immunoprecipitation or immunoblotting with both monoclonal (Mab 517 and Mab 601) and polyclonal antibodies, we observed that carcinoembryonic antigen was actually expressed as two discrete apparent molecular weight forms in normal tissues: a broad band averaging at Mr 200,000 and a sharp band at Mr 130,000. This constituted the phenotype of the normal colon. In cancer cells we detected a single band at Mr 170,000 or lower. This variation was mainly the consequence of a modification of the glycosylation pattern of the molecule since deglycosylation by N-glycanase or biosynthesis in the presence of tunicamycin always produced a single molecular weight form, whether or not the source of tissue was normal or cancerous. By close inspection of benign, moderately transformed, and carcinomatous human colonic polyps we noticed that this shift in the molecular weight of carcinoembryonic antigen preceded the detection of other cancer markers such as nonspecific cross-reacting antigen at Mr 95,000 or the histological modifications leading to malignant diagnosis. Carcinoembryonic antigen constitutes, therefore, an important model with which to study the modifications of the glycosylation pattern induced during cancer biogenesis.

Carcinoembryonic Antigen↗