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PubMed1984

Piecemeal snare excision of large sessile colon and rectal polyps: is it adequate?

This study analyzes 28 consecutive patients with large sessile polyps snared piecemeal from the colon and rectum. The sections were examined to determine the adequacy of orientation and margin of excision. Orientation was judged excellent in five, good in 12, fair in six, and poor in five cases. The margin of excision was judged adequate in 23 of 28 cases. Five of eight patients with invasive carcinoma underwent bowel resection, and no residual tumor was found in the resected specimens. Of the remaining 20 patients without carcinoma, five had residual tumor or recurrences, with follow-up from 6 months to 6 years (average, 18 months). All of them underwent rebiopsies and electrocoagulation. None of the residual tumor or recurrences showed evidence of malignancy. Piecemeal snare excision of large sessile polyps of the large bowel appears to be an adequate procedure for most patients. A close follow-up with colonoscopy or proctoscopy is essential because residual tumor or recurrences are common.

Colonic Polyps↗

PubMed2004

The effect of reconstruction algorithm on conspicuity of polyps in CT colonography.

OBJECTIVE: CT colonography studies to date have used a standard CT algorithm. To determine whether nonstandard algorithms may result in better performance of CT colonography, we conducted a prospective, blinded-observer study of the effect of the reconstruction algorithm on the conspicuity of colonic polyps and folds. SUBJECTS AND METHODS: CT colonography of patients with proven polyps, masses, or polypoid folds was performed on an MDCT scanner, and the images were reconstructed using the standard, soft, lung, and detail algorithms. Two experiments were performed. The first used four patient data sets of a short segment of colon (30-60 images), each reconstructed using all four algorithms and then viewed on a workstation in a four-on-one format that allowed all four reconstructions to be viewed simultaneously. The second used six sets of cut-film images (four or eight images each); images within each set differed only in the reconstruction algorithm used to generate them (eight-image sets were prepared with two different level settings). Twenty-one reviewers with varying levels of experience who were unaware of the purpose of the study were asked to rank the images within each set according to their value in the detection of either polyps or masses. RESULTS: Reviewers showed statistically significant differences in preference for the four algorithms (p = 0.037 in the computer-based experiment; for the cut-film experiment, p = 0.029 for the four-image sets and p = 0.041 for the eight-image sets). In the computer-based experiment, reviewers preferred the detail algorithm to the standard algorithm with an estimated probability of 0.67 (95% confidence interval [CI], 0.57-0.75) and the soft algorithm over the standard algorithm with an estimated probability of 0.59 (95% CI, 0.51-0.66). However, reviewers with the most experience (having interpreted at least 250 cases) preferred the soft algorithm over the standard algorithm by the same two-to-one margin as observed for the detail algorithm. In contrast, the standard and detail algorithms were ranked similarly in the cut-film experiment, with the soft and lung algorithms ranked worst. CONCLUSION: To our knowledge, ours is the first observer study on the effect of the reconstruction algorithm on conspicuity of folds and polyps in CT colonography. Our results indicate significant differences in the reconstruction algorithms, with the soft and detail algorithms being preferred over the standard algorithm by experienced reviewers when interpreting images on a workstation. These results indicate the need for further research into the effect of reconstruction algorithms on CT colonography.

Algorithms↗

PubMed1989

[Inflammatory giant polyps of the colon].

Five cases of inflammatory giant polyps associated with idiopathic colitis are presented. The underlying disease was ulcerative colitis in 3 cases and Crohn's disease in 2 cases. The alteration caused in 3 cases passage disorders. Physical and X-ray examinations raised the possibility of malignancy, thus operation was performed. In 2 further cases endoscopic polypectomy brought improvement and the operation could be avoided. On the basis of electronmicroscopic examination the authors are of the opinion that giant polyps are specific forms of inflammatory granulation with fibroblasts, myofibroblasts, vessels, mast cells and extended autonomous nerves as dominant elements. It is held as feasible that due to the nerves and contractile myofibroblasts these forms are capable to move actively. This might explain the peduncle formation and - together with the passage disorders- the strong abdominal spasm characterizing the clinical picture.

Adult↗

PubMed2006

Expression of transporters potentially involved in the targeting of cytostatic bile acid derivatives to colon cancer and polyps.

Drug targeting might help to overcome resistance to chemotherapy. Here we investigated whether colon cancer and polyps do express functional carriers involved in the uptake of cytostatic bile acid derivatives, in this case Bamet-UD2 [cis-diammine-bisursodeoxycholate-platinum(II)], which has been reported to be taken up by colon cancer cells "in vitro", efficiently induce apoptosis and overcome resistance to cisplatin. Although at lower levels than in ileum, a detectable expression of ASBT, OATP8/1B3, OCT1 and OSTalpha in colon tissue was found, which was not impaired in colon cancer or polyps. The expression of OATP-A/1A2 and OSTbeta was also found in colon, but this was markedly decreased in neoplastic colon tissue. In contrast, the expression of OATP-C/1B1 was low in colon but significantly enhanced in neoplastic colon tissue. MDR1 and MRP2 were poorly expressed in colon as compared with ileum, whereas MRP3 expression was higher in colon than in ileum. The abundance of mRNA for these ABC proteins was not changed in colon cancer or polyps. When RNA from different tissues was injected to Xenopus laevis oocytes their ability to take up taurocholate and Bamet-UD2 was enhanced (healthy ileum>healthy colon approximately neoplastic colon tissue). In all cases, uptake was lower for taurocholate than for Bamet-UD2, probably due to that ASBT mediates sodium-dependent uptake of both substrates, whereas additional transporters expressed in these tissues can participate in Bamet-UD2 uptake. In conclusion, our results suggest that the use of cytostatic bile acid derivatives might be a good pharmacological strategy for the treatment of colon tumors.

Animals↗

PubMed1981

Electron microscopy of polyps of the colon. I. Comparative study of the epithelial cells of adenomatous and adenopapillary polyps.

By comparing the electron-microscopic pictures of adenomatous and adenopapillary polyps, the ultrastructural characteristics of premalignant epithelial dysplasia were studied. In highly differentiated adenomatous polyps, the ratio and the electron-microscopic appearance of absorptive and goblet cells did not differ from the epithelial cells of the normal mucosa of the colon. In the dysplastic regions of adenopapillary polyps, the intensive proliferation in several layers of undifferentiated epithelial cells, and the maturation disorder of absorptive and goblet cells, were observed. Severe changes occurred on the cell membrane as well as atypical vacuoles and dense bodies in the apical regions of the cell membrane. Several inclusion bodies of Leuchtenberger were observed, these being considered an important characteristic of malignant transformation.

Basement Membrane↗

PubMed1998

Genetic alterations of mixed hyperplastic adenomatous polyps in the colon and rectum.

Some mixed hyperplastic adenomatous polyps (MHAPs) contain dysplastic lesions or even carcinomas. These polyps are considered to be different from ordinary hyperplastic polyps and may have a preneoplastic potential. We investigated APC and K-ras mutations in MHAPs of the colon and rectum, and also in colorectal adenomas and hyperplastic polyps to identify molecular differences between MHAPs, adenomas and hyperplastic polyps, using direct sequencing of mutation cluster regions (MCR) in APC and K-ras. No APC mutations were identified in 12 MHAPs and 8 hyperplastic polyps, whereas 10 of 27 (37.0%) adenomas showed somatic mutations. K-ras mutations were identified in one of 12 (8.3%) MHAPs, one of 8 (12.5%) hyperplastic polyps, and 10 of 27 (37.0%) adenomas. p53 mutation was found in a carcinoma arising in an MHAP. Mutations other than APC mutations may play a role in the development of MHAPs.

Adenoma↗

PubMed1983

[Possibilities of partial and total biopsy of polyps of the large intestine during fiber-colonoscopy].

222 electric polypectomies were performed in the course of fibrocolonoscopy carried out in 114 patients. The results of examination of 172 removed neoplasms testified to the high effectiveness of the procedure in identifying the morphological structure of colonic polyps. Due to application of endoscopic polypectomy, which is essentially a total biopsy, histological diagnosis obtained on the basis of aiming biopsy was improved or modified in 67% of cases. However, aiming biopsy should be used because more than 20% of resected polyps fail to be removed from colonic lumen.

Biopsy↗

PubMed1997

[Hyperplastic polyps of the colon. An inhomogeneous group of pathologic-anatomic changes].

A total of 334 hyperplastic polyps of the colon of 266 patients were examined under epidemiologically, morphometrically and histochemically. Of these, 62 cases (23%) were associated with adenomas, 18 cases (7%) with carcinomas. Hyperplastic polyps are not entirely homogeneous, pathologically and -anatomically: Carcinoma-associated hyperplastic polyps are larger in diameter, the size and width of their crypts is greater, and they have a higher percentage of goblet cells with a higher amount of sialomucins as shown by HID/AB stain.

Adenomatous Polyps↗

PubMedDate not supplied

A gastrointestinal-specific monoclonal antibody that may be of clinical value in cytologic material.

A new monoclonal antibody (MAb), 29-10, produced by immunization of mice with cells from the SW 1116 colorectal carcinoma cell line, detected an antigen present in cytologic touch imprints of surgically resected normal and neoplastic gastrointestinal (GI) tissue, including specimens from the stomach and the colon. These imprints were fixed in 95% ethanol and stained with the avidin-biotin immunoperoxidase technique. In tested cases, 22 (100%) of 22 imprints from GI adenocarcinomas and from normal GI tissue, as well as 13 (56.6%) of 23 imprints from colonic polyps, stained positively while no staining was demonstrable in imprints from other tissues. In histologic sections, only 4 (23%) of 17 colonic adenocarcinomas and 3 (11.5%) of 26 polyps stained positively. The staining ability of MAb 29-10 was compared to that of MAb 19-9, another colorectal antibody, and was found to be markedly superior for binding of the antigen in cytologic preparations. This tissue-specific antibody may be useful in identifying malignant cells of metastatic carcinoma as to their GI tract origin.

Adenocarcinoma↗

PubMed1962

Do adenomatous polyps of the colon become malignant?

Explore the source record for details and available documents.

Adenomatous Polyps↗

PubMed1991

Peutz-Jeghers syndrome associated with adenocarcinoma of the cecum and focal carcinomas in hamartomatous polyps of the colon: a case report.

We report herein a case of Peutz-Jeghers syndrome associated with an adenocarcinoma of the cecum and four focal cancers arising in hamartomatous polyps of the colon. There were a total 27 polyps in the intestine; 4 in the small intestine and the rest in the large intestine. The hamartomatous polyps in which the 4 focal cancers were found showed no component of adenoma, and the other polyps removed from the colon and small intestine at the same time were all hamartomas with no evidence of dysplasia or malignancy. This case was rare in that multiple focal cancers may have arisen directly from the hamartomous polyps of the colon.

Adenocarcinoma↗

PubMed2005

Something not quite right: Gardner syndrome diagnosed by multiple cutaneous lesions and genetic testing.

Gardner syndrome is a variant of familial adenomatous polyposis characterized by intestinal adenomatous polyps, which can progress to adenocarcinoma, and a variety of extraintestinal manifestations, including skin cysts, osteomas, soft tissue fibrous tumours and a characteristic ocular lesion. The extraintestinal manifestations are often the presenting feature but are usually not sufficiently characteristic on their own to trigger recognition of the syndrome. We report a case of a 17-year-old female who had been treated by a number of specialists over a 13-year period for a variety of cutaneous lesions without a hereditary condition being suspected. Gardner syndrome was considered only after excision of subcutaneous fibrous tumours from the mastoid region and paraspinal area and was confirmed by genetic testing in spite of the patient's refusal to undergo colonic endoscopic examination. Subsequent resection revealed approximately 70 adenomatous colonic polyps in the colon and rectum but no invasive tumour, highlighting the benefits of genetic testing in treatment planning.

Adolescent↗

PubMed1995

A case of Peutz-Jeghers syndrome with nasal polyposis, extreme iron deficiency anemia, and hamartoma-adenoma transformation: management by combined surgical and endoscopic approach.

We report a rare variant of Peutz-Jeghers syndrome identified by the presence of nasal polyposis and extreme anemia. Multiple hamartomatous polyps were found throughout the upper and lower gastrointestinal tract. We conducted a combined surgical-endoscopic approach to prevent the development of a short-bowel syndrome. The polyps removed by snare and surgical polypectomy showed features typical of harmartomas. Three colonic polyps and two nasal polyps showed histological evidence of adenomatous change. This adenomatous change seems to fit into the pathogenic sequence of hamartoma-adenoma.

Adult↗

PubMed1995

Increased N-myristoyltransferase activity observed in rat and human colonic tumors.

BACKGROUND: Colorectal cancer is one of the leading causes of cancer death in North America. Since treatment of colonic cancer remains difficult because of the lack of effective chemotherapeutic agents, it is important to continue to search for cellular functions that can be disrupted by chemotherapeutic drugs and inhibit the development or progression of this disease. Modification of proteins by myristoylation has been recognized as important in the function of various viral, oncogenic, and signal-transduction proteins and thus has been proposed as a target for chemotherapeutic drug design. However, the activity of the enzyme that catalyzes this modification, N-myristoyltransferase, has not been investigated in cancer relative to normal tissue. PURPOSE: The purpose of this study was twofold: 1) to investigate the activity of N-myristoyltransferase in azoxymethane-induced rat colonic cancer tissue compared with normal and normal-appearing rat colonic tissue and 2) to determine if similar differences would be observed in a small sample of human colonic tumors. METHODS: N-Myristoyltransferase activity was determined in 45 colonic tissue specimens from Sprague-Dawley rats--10 given injections of the colon carcinogen, azoxymethane, and three untreated. Tissue specimens included 35 colonic tumors of varying pathologic stages, seven specimens of normal-appearing adjacent mucosa, and three specimens of normal colonic mucosa. Colectomy specimens from five patients were assayed for N-myristoyltransferase activity. Subcellular distribution of N-myristoyltransferase activity was determined. Synthetic peptides of known myristoylated proteins--pp60src and cyclic adenosine monophosphate-dependent protein kinase--were used in kinetic analyses of N-myristoyltransferase in colonic cancer and normal-appearing colonic tissue. All P values are two-tailed. RESULTS: N-Myristoyltransferase activity was increased in rat colonic tumors compared with normal-appearing adjacent mucosa and normal mucosa (P = .0002). Elevation of N-myristoyltransferase activity was present in all tumors, including colonic polyps. Increased N-myristoyltransferase activity was also observed in human colonic tumors and was predominantly cytosolic. N-Myristoyltransferase of colonic cancer tissues had a similar Michaelis constant but an approximate twofold higher maximum velocity for both the pp60src- and cyclic adenosine monophosphate-dependent protein kinase-derived peptides compared with N-myristoyltransferase of normal-appearing tissue. CONCLUSIONS: This study demonstrates for the first time that N-myristoyltransferase activity is higher in colonic epithelial neoplasms than in normal-appearing colonic tissue and that an increase in N-myristoyltransferase activity appears at an early stage in colonic carcinogenesis.

Acyltransferases↗

PubMed2004

Prevalence of occult celiac disease in patients with iron-deficiency anemia: a prospective study.

BACKGROUND: Occult celiac disease has been reported in 0 to 6% of adults presenting with iron-deficiency anemia. Most prior studies have been retrospective or screened only a selected population of patients with small bowel biopsies. To more accurately define the true prevalence of this disorder in patients presenting with iron-deficiency anemia (with or without stool hemoccult positivity), we initiated this prospective study. METHODS: Esophagogastroduodenoscopy with small bowel biopsies and colonoscopy were performed in all iron-deficiency anemia patients (including those with hemoccult-positive stools) referred to the gastroenterology service during a 2-year period (1998-2000). Inclusion criteria included iron-deficiency anemia as defined by a serum ferritin < 25 ng/ml and anemia with hemoglobin < 12 g/dl. Patients were excluded for documented prior erosive, ulcerative, or malignant disease of the gastrointestinal tract, previous gastrointestinal surgery, overt gastrointestinal bleeding within the past 3 months, or inability to access the duodenum for biopsy. All patients underwent upper endoscopy with more than two biopsies of the distal duodenum and colonoscopy. A serum immunoglobulin A antiendomysial antibody test was to be performed in those patients with a positive small bowel biopsy to confirm the diagnosis of celiac disease. RESULTS: One hundred five of 139 consecutive patients with iron-deficiency anemia met the inclusion criteria and were enrolled in the study. Fifty-seven men (mean age, 51.6 yr) and 48 women (mean age, 54.1 yr) constituted the study population. The demographics of this study population included 36 blacks, 38 Hispanics, and 22 whites. Nine patients were of mixed or unknown ethnic background. Forty-three and eight-tenths percent of the men and 37.5% of women had hemoccult-positive stools, accounting for a total of 40.9% of the study patients. Upper endoscopic findings included gastritis in 22.8%, gastric ulcers in 9.5%, duodenitis in 8.5%, esophagitis in 7.6%, Barrett's ulcer in 2.8%, duodenal ulcer in 2.8%, gastric polyp in 2.8%, and celiac disease in 2.8%. Colonoscopic findings included colon polyps in 21.9%, diverticula in 10.4%, and hemorrhoids in 16.1%. Multiple findings were found in 32.3% of patients, and there were no findings in 28.5% of patients. CONCLUSION: The prevalence of occult celiac disease in this prospective study of patients presenting with iron-deficiency anemia was 2.8%. A significant number of other gastrointestinal lesions amenable to therapy were also found on upper and lower endoscopy in these patients. Given the treatable nature of celiac disease, it should be screened for in patients with unexplained iron-deficiency anemia with or without hemoccult-positive stools.

Anemia, Iron-Deficiency↗

PubMed1994

Monoclonal antibody COL-1 reacts with restricted epitopes on carcinoembryonic antigen: an immunohistochemical study.

We used a monoclonal antibody, MAb COL-1, which recognized a restricted epitope on the carcinoembryonic antigen (CEA) molecule, to stain a wide variety of human normal and cancerous tissues. None of the 35 different types of normal tissue stained with COL-1. Of 59 types of benign and malignant tissues, COL-1 reacted with neoplasms of epithelial origin, especially the gastrointestinal tract, breast, lung, and bladder. In benign adenomatous colon polyps, villous adenomas were more frequently stained than tubular adenomas. Normal colon tissue from individuals without colon disease was unreactive, but very weak reactivity was noted in normal-appearing mucosa several centimeters remote from colon cancers. In contrast, another anti-CEA antibody with a less restricted epitope reacted frequently with both normal and remote colon mucosa. These results indicate that MAb COL-1 recognizes a restricted CEA epitope expressed only on pre-malignant or malignant cells and therefore may be a useful reagent for immunopathology.

Antibodies, Monoclonal↗

PubMed2002

Assessment of faecal occult blood loss by qualitative and quantitative methods.

BACKGROUND: Various methods exist for the assessment of faecal occult blood loss in a patient with suspected gastrointestinal blood loss. METHODS: The present study examined the effectiveness and financial implications of a qualitative guaiac-based method (Haemoccult) of faecal occult blood detection and a quantitative measure of haeme-derived porphyrins (Hemoquant) in 184 patients who underwent assessment of faecal blood loss by both methods over a three year period during assessment of iron deficiency anaemia. MAIN FINDINGS: At least one Haemoccult test was positive in 72.2% of patients while Hemoquant was suggestive of significant blood loss (> 2mg haemoglobin/g faeces) in 29.9%. Patients underwent a total of 324 further endoscopic or radiological investigations of which 76.5% demonstrated no abnormality. A diagnosis was reached in 60 patients (32.6%). A significant potential source of gastrointestinal bleeding was found in 48 patients (26.1%). Hemoquant achieved a sensitivity of 62.5% and a specificity of 81.6% while with Haemoccult it was 85.4% and 32.4%, respectively. Hemoquant was normal in 18 patients with significant gastrointestinal conditions including peptic ulcers and colonic polyps. While Haemoccult only missed 7 lesions, two of these were colonic cancers. The quantitative nature of the Hemoquant test gave little clue as to diagnosis. CONCLUSION: Neither of the tests examined was ideal but Hemoquant had an overall better performance and further investigation of patients with evidence of blood loss from this test should be mandatory.

Adolescent↗

PubMed1997

Morphological and molecular processes of polyp formation in Apc(delta716) knockout mice.

Mutations in the human adenomatous polyposis coli (APC) gene are responsible for not only familial adenomatous polyposis but also many sporadic cancers of the digestive tract. Using homologous recombination in embryonic stem cells, we recently constructed Apc gene knockout mice that contained a truncation mutation at codon 716 (Apc(delta716)). The heterozygous mice developed numerous intestinal polyps. All microadenomas dissected from nascent polyps had already lost the wild-type allele, indicating the loss of heterozygosity (M. Oshima et al., Proc. Natl. Acad. Sci. USA, 92: 4482-4486, 1995). We also demonstrated that cyclooxygenase 2 is induced in the polyps at an early stage and plays a key role in polyp development (M. Oshima et al., Cell 87: 803-809, 1996). We have analyzed the process of polyp development in these mice both at morphological and molecular levels. A small intestinal microadenoma is initiated as an outpocketing pouch in a single crypt and develops into the inner (lacteal) side of a neighboring villus forming a double-layer nascent polyp. The microadenoma then enlarges and gets folded inside the villus. When it fills the intravillous space, it expands downward and extends into adjoining villi, rather than rupturing into the intestinal lumen. During this course of development, the basement membrane remains intact, and the labeling index of the microadenoma cells is similar to that of the normal crypt epithelium. As in the crypt cells, neither transforming growth factor beta1 nor its receptor type II is expressed in the microadenoma cells. No hot spot mutations in the K-ras gene are found in the microadenoma tissue during these early stages of polyp development. Essentially, the same results have been obtained for the colonic polyps as well. These results suggest that early adenomas in the Apc(delta716) polyps are very similar to the normal proliferating cells of the crypt except for the lack of directed migration along the crypt-villus axis.

Activin Receptors, Type I↗