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At least 1,063 records · Page 59Linked to original sources
PubMed2004

Benign fibroblastic polyps of the colon: a histologic, immunohistochemical, and ultrastructural study.

Mesenchymal proliferations presenting as mucosal polyps are relatively uncommon and are represented by gastrointestinal stromal tumors, smooth muscle and neural tumors, and inflammatory fibroid polyps. In this report, we describe the clinicopathologic features of a distinctive type of mucosal polyp composed of cytologically bland spindled cells with fibroblastic features. Fourteen cases with histologic features of"fibroblastic polyps" were identified from our case files from January 2000 to December 2003. The clinical and endoscopic findings were reviewed. Immunohistochemistry using a panel of antibodies (vimentin, smooth muscle actin, desmin, CD31, CD34, Bcl-2, c-Kit, S-100, and epithelial membrane antigen) was performed in all cases, and electron microscopy was performed in two cases. The lesions were solitary in all cases and not associated with an identifiable polyposis syndrome. Associated adenomata and/or hyperplastic polyps at different sites were present in 10 cases and hyperplastic polyps were seen in close association in 3 cases. These polyps were characterized by a monomorphic spindle cell proliferation in the lamina propria, without necrosis or mitotic activity. The lesions were intimately associated with the muscularis mucosae and resulted in wide separation and disorganization of the colonic crypts. Immunohistochemical analysis revealed strong and diffuse positivity for vimentin only. Weak and focal reactivity was noted in 2 cases for CD34 and smooth muscle actin, while staining for other antibodies was negative. Electron microscopy revealed sparse cytoplasmic organelles and many intermediate filaments. The histology and ultrastructural and immunohistochemical findings are suggestive of fibroblastic differentiation of these spindle cells. In summary, these lesions represent a distinctive type of colonic mucosal polyp that should be distinguished from other stromal polyps of the gastrointestinal tract.

Actins↗
PubMed2006

Detection of colorectal lesions by using autofluorescence colonoscopy in acromegalics and their relation to serum growth hormone and insulin-like growth factor-1 levels.

OBJECTIVES: Acromegalics have an increased risk of colorectal neoplasm. The aim of this study was to establish the association between acromegaly and colorectal lesions. MATERIALS AND METHODS: The study included 51 patients with active acromegaly: 30 women and 21 men (average age 52.95 +/- 13.49 years). Growth hormone (GH), insulin-like growth factor I (IGF-I), prolactin (PRL), thyreothropin (TSH), thyroxine (FT4) were measured in the serum when patients were hospitalized for their first diagnosis of acromegaly, before starting the treatment. All patients underwent colonoscopy--in the first phase conventional in white light; in the second phase fluorescence colonoscopy. Autofluorescence of colonic mucosa was assessed by illumination with monochromatic light. Green fluorescence is characteristic for normal colonic mucose, whereas red fluorescence occur in pathological lesions. Material to histopathological examination was taken from every pathological colorectal lesion. RESULTS: Using conventional colonoscopy we detected colonic polyps in 21 acromegalic patients (41.17%). Polyps with red fluorescence were found in 7 (13.7%) acromegalics and with green fluorescence in 16 (31.37%) cases of these patients. Histological diagnoses of colorectal lesions are adenoma, hyperplastic and inflammatic polyps. The number of colorectal polyps was dependent on IGF-I, fT4 and sex. CONCLUSIONS: Acromegaly is associated with high prevalence of colorectal pathology, mainly hyperplastic polyp and adenoma. There is a relationship between number of colorectal polyps and serum IGF-I levels in acromegaly. Adenomas and hyperplastic polyps were associated with higher levels of IGF-I.

Acromegaly↗
PubMed2004

Value of magnification endoscopy in current clinical practice.

Ongoing technological developments in endoscopy have led to an ever improving evaluation and management of digestive diseases. The recent development of a new range of high-power magnification, or zoom, endoscopes has boosted interest in this technique, which has become increasingly available to the modern gastroenterologist. Magnification is often used in conjunction with chromoendoscopy in order to improve the detection and diagnosis of neoplastic tissue. Currently, the main clinical indications are the diagnosis of Barrett oesophagus, the colonoscopic surveillance of colonic polyps and the assessment of disease severity or the presence of dysplasia in inflammatory bowel disease. In this article we present an overview of the clinical implementations of magnification endoscopy in current and future gastroenterological practice.

Barrett Esophagus↗
PubMed2007

CT colonography: techniques, indications, findings.

Computed tomographic colonography (CTC) is a minimally invasive technique for imaging the entire colon. Based on a helical thin-section CT of the cleansed and air-distended colon, two-dimensional and three-dimensional projections are used for image interpretation. Several clinical improvements in patient preparation, technical advances in CT, and new developments in evaluation software have allowed CTC to develop into a powerful diagnostic tool. It is already well established as a reliable diagnostic tool in symptomatic patients. Many experts currently consider CTC a comparable alternative to conventional colonoscopy, although there is still debate about its sensitivity for the detection of colonic polyps in a screening population. This article summarizes the main indications, the current techniques in patient preparation, data acquisition and data analysis as well as imaging features for common benign and malignant colorectal lesions.

Colonic Polyps↗
PubMed2003

Should patients on warfarin for 3 months for idiopathic proximal deep venous thrombosis receive bridging therapy precolonoscopy (with expected biopsy)?

A 63-year-old woman presents to discuss periprocedure anticoagulation management. She has been on oral warfarin with an international normalized ratio between 2 and 3 for the past 3 months because of an idiopathic left popliteal vein thrombosis. A colonic polyp was identified during her purely diagnostic colonoscopy performed as part of her age- and gender-appropriate cancer screening. Immediate repeat colonoscopy with polypectomy is recommended. The clinician is asked to provide periprocedural anticoagulation recommendations.

Anticoagulants↗
PubMed2006

The use of acetic acid in magnification chromocolonoscopy for pit pattern analysis of small polyps.

BACKGROUND AND STUDY AIMS: The role of acetic acid spray during magnification chromocolonoscopy has not previously been evaluated. We aimed to compare the accuracy of predicting polyp histology at magnification colonoscopy, using acetic acid and indigo carmine, either alone or in combination. PATIENTS AND METHODS: A total of 46 consecutive patients with polyps detected during colonoscopy which measured 10 mm or less were alternately divided into two groups. In group A patients, 1.5 % acetic acid was applied to the mucosa first, followed by indigo carmine spray; in group B patients, the order was reversed. The pit pattern was assessed after application, in real time. All the lesions were resected and examined histologically. RESULTS: Altogether, 37 adenomas and 36 hyperplastic polyps were evaluated. In group A, the diagnostic accuracy after spraying with acetic acid was 95 %, which increased to 98 % after application of indigo carmine. In group B, the accuracy after indigo carmine application was 83 %. After subsequent spraying with acetic acid, images were enhanced in 70 % of patients, with an increase in accuracy to 97 %. The mean time required to obtain an initial clear image with the first dye was 14 seconds for both groups. CONCLUSIONS: This is the first description of the use of acetic acid for pit pattern analysis of colonic polyps. Its ease of use, low cost, and safety, together with its excellent accuracy in the assessment of polyp pit patterns suggest that this method could easily be applied to routine magnification colonoscopy.

Acetic Acid↗
PubMed1991

Colonoscopic surveillance after polypectomy: considerations of cost effectiveness.

OBJECTIVE: To assess the cost effectiveness of the current recommendation that persons who have had an adenomatous colon polyp removed have periodic colonoscopic surveillance at fixed and regular intervals. DESIGN: Cost-effectiveness analysis using data from the medical literature in a simulation model to estimate the costs of and the risk for perforation associated with periodic colonoscopic surveillance for a 50-year-old man followed for 30 years. MAIN RESULTS: A program of colonoscopy every 3 years would incur cumulatively a 1.4% risk for colon perforation, a 0.11% risk for perforation-related death, and direct physician costs of $2071 for colonoscopy (discounted at 5%). If a 50-year-old man's cumulative remaining risk for death from cancer is 2.5% after the removal of a single small adenoma and if effectiveness of colonoscopic surveillance every 3 years is 100%, then one death from cancer could be prevented by doing 283 colonoscopies, incurring 0.6 perforations, 0.04 perforation-related deaths, and direct physician costs of $82,000. If surveillance were 50% effective and the cumulative remaining risk for death from cancer were 1.25%--a plausible scenario--1131 colonoscopies would be required to prevent one death from cancer, incurring 2.3 perforations, 0.17 perforation-related deaths, and physician costs of $331,000. CONCLUSIONS: The cost effectiveness of colonoscopic surveillance is very sensitive to estimates of the cumulative remaining risk for death from cancer after polypectomy as well as to surveillance efficacy. For persons whose remaining risk for death from cancer may be low, such as persons with a single small adenoma, recommendations for colonoscopic surveillance at fixed and regular intervals may be excessively costly.

Aged↗
PubMed2001

Faecal calprotectin and faecal occult blood tests in the diagnosis of colorectal carcinoma and adenoma.

BACKGROUND AND AIMS: Testing for faecal occult blood has become an accepted technique of non-invasive screening for colorectal neoplasia but lack of sensitivity remains a problem. The aim of this study was to compare the sensitivity and specificity of faecal calprotectin and faecal occult blood in patients with colorectal cancer and colonic polyps. METHODS: Faecal calprotectin and occult blood were assessed in 62 patients with colorectal carcinoma and 233 patients referred for colonoscopy. The range of normality for faecal calprotectin (0.5-10.5 mg/l) was determined from 96 healthy subjects. RESULTS: Median faecal calprotectin concentration in the 62 patients with colorectal carcinoma (101 mg/l, 95% confidence interval (CI) 57-133) differed significantly from normal (2.3 mg/l, 95% CI 1.6-5.0) with 90% of patients having elevated levels (normal <10 mg/l) whereas only 36/62 (58%) had positive faecal occult bloods. There was no significant difference in faecal calprotectin levels when considering location or Dukes' staging of tumour. Percentage positivity of faecal occult bloods was significantly higher for Dukes' stage C and D cancers compared with Dukes' A and B. In the colonoscopy group, 29 patients with adenomatous polyps were detected in whom the median faecal calprotectin was 12 mg/l (95% CI 2.9-32). Sensitivity for detection of adenomatous polyps was 55% using the calprotectin method and 10% using faecal occult blood testing. The overall sensitivity and specificity of calprotectin for colorectal cancer and adenomatous polyps as a combined group was 79% and 72%, respectively, compared with a sensitivity and specificity of faecal occult blood of 43% and 92%. CONCLUSIONS: Faecal calprotectin is a simple and sensitive non-invasive marker of colorectal cancer and adenomatous polyps. It is more sensitive than faecal occult blood tests for detection of colorectal neoplasia at the cost of a somewhat lower specificity.

Adenoma↗
PubMed1995

Endoscopic polypectomy for pacemaker patients.

Endoscopic polypectomy using high frequency voltage is contraindicated in patients with cardiac pacemakers. Recently, highly advanced pacemakers have enabled us to perform endoscopic polypectomy on these patients by taking appropriate cautions. We successfully removed 10 colonic polyps and one gastric polyp in patients with pacemakers by endoscopic polypectomy. No complication and dysfunction of the pacemaker occurred before, during or after the polypectomy.

Aged↗
PubMed1975

The detection of aberrant DNA synthesis in a member of a high-risk cancer family.

Relatives of patients with multiple polyposis are among those at high risk for development of neoplasms in the colon. Examination of 4 siblings, 3 men and 1 woman, of a patient with multiple polyposis was conducted for the possible presence of colonic polyps. All patients were over 40 years of age and received barium enemas for the radiological detection of excrescences. Proctoscopic examinations were also carried out during which time a biopsy and colonic wash were obtained. Polyps were absent on films as well as on endoscopy, and colonic cytologies of all 4 subjects were within normal limits. However, isotopic incorporation studies revealed the presence of an abnormal labeling pattern in some crypts of the biopsy incubated with TdR-3H of 1 family member. Along with normal crypts with label in the lower two-thirds of the colonic crypts, some were seen to have cells labeled at the surface, a proliferative lesion thought to precede the apperarance of a polyp. Among the surface cells removed by the colonic wash, some were found to be isotopically labeled, that is, engaged in DNA synthesis. Thus, a defect in the regulation of colonic epithelial cell replication was found, suggesting the need for close surveillance in the interest of early colon cancer detection.

Adult↗
PubMed1997

Expression of E-cadherin-associated molecules (alpha-, beta-, and gamma-catenins and p120) in colorectal polyps.

E-cadherin and its associated cytoplasmic proteins alpha-, beta-, and gamma-catenin and p120 protein play a crucial role in the maintenance of normal tissue architecture. Perturbation in any of these molecules results in loss of intercellular adhesion and cell transformation. In this study, we have used immunohistochemistry to localize E-cadherin, alpha-, beta-, and gamma-catenin, and p120 in paraffin-embedded tissues from 60 patients with colonic polyps. Specimens consisted of 20 samples each from hyperplastic, inflammatory, and sporadic adenomatous polyps. Ten histologically normal colonic samples were also studied. Normal colonic epithelial cells showed strong E-cadherin/ catenin/p120 immunostaining at the cell-cell junction. In 65% (13/20) of adenomatous polyps, beta-catenin showed abnormal nuclear localization with increased expression and loss of membranous staining compared with the adjacent normal mucosa. In two cases (10%), gamma-catenin was seen in the nuclei. Heterogeneous p120 immunoreactivity was observed in four cases (20%), of which two also showed beta-catenin nuclear localization. Preserved membranous alpha-catenin staining was seen in all cases. E-cadherin was down-regulated in 6 of 20 (30%) adenomas with loss of cell surface staining in 3 cases. All hyperplastic and 40% (8/20) of inflammatory polyps showed weak E-cadherin expression on the surface epithelium. Similar changes in p120 expression were seen in all hyperplastic and 20% (4/20) of inflammatory polyps. There were no concomitant changes in alpha-, beta-, or gamma-catenin expression. These results indicate that changes in catenin expression and cellular localization occur early in dysplastic colonic lesions.

Adenomatous Polyps↗
PubMed1987

Nonfamilial intestinal polyposis and brain tumor in a 5-year-old girl.

A 5-year-old girl with glioblastoma multiforme and simultaneous adenocarcinoma in one of multiple colonic polyps is the youngest reported case of Turcot's syndrome. A literature survey and a classification based on family pedigree and pattern of inheritance are proposed.

Adenocarcinoma↗
PubMed1998

[Significance of CT in the detection of regional lymph node metastases in colorectal carcinoma].

PURPOSE: For preoperative staging of colorectal cancer a CT scan is frequently performed. This report examines the sensitivity of CT for regional lymph node metastasis of colorectal cancer using different criteria. MATERIALS AND METHODS: Preoperative CT scans of 153 patients with colorectal cancer were analyzed using different criteria for N1. The results were then compared to the postoperative histological findings. RESULTS: For N1 = lymph nodes (LN) > 1 cm the sensitivity was 47%. For N1 = LN > 1 cm or an increased number of LN < 1 cm the sensitivity was 71%. In patients with a primary tumor seen on CT, sensitivity rose to 87%. DISCUSSION: Evidence of regional nodal metastatic disease is only relevant for rectal cancer, colon polyps, and for locally excised tumors when considering present surgical concepts for the treatment of colorectal cancer. In these cases CT analysis using the broadened criteria for N1 proposes a valuable argument regarding possible preoperative radiotherapy or an operative revision.

Aged↗
PubMed2002

Isolation and sequencing of a novel tropomyosin isoform preferentially associated with colon cancer.

BACKGROUND & AIMS: Nonmuscle human tropomyosin (hTM) isoforms have distinct functions and may play important roles in various disease processes. METHODS: In an attempt to identify colon epithelial tropomyosin isoform, a complementary DNA library prepared from a human colon cancer cell line T84 was screened by an oligonucleotide probe complementary to messages of all known hTM isoforms. A novel clone called TC22 was obtained. The amino acid sequence of TC22 isoform is identical to isoform 5 (hTM5) apart from the C terminal domain, amino acids 222-247 coding the exon 9. RESULTS: Northern blot analysis showed that TC22 message is expressed in transformed epithelial cell lines and tumor tissues but not in normal epithelial cells. We developed a monoclonal antibody specific to TC22 isoform (TC22-4). By Western blot and immunoperoxidase assays, we analyzed 105 colonic specimens (fresh frozen and formalin fixed) from 96 patients with colon polyps (hyperplastic) or adenomas with or without dysplasia and cancer. Twenty-one of 22 (95%) of colon cancer specimens showed the presence of TC22, compared with only 1 of the 17 normal colon specimens and none of the 13 hyperplastic polyps (P < 0.0001). As assayed by immunoperoxidase staining, TC22 expression progressively increased in benign adenomatous polyps (35%) and polyps with mild and severe dysplasia (57% and 100%, respectively). CONCLUSIONS: We cloned and sequenced a novel hTM isoform, TC22, which is strongly associated with colonic neoplasia and carcinoma. TC22 may provide a useful biomarker for surveillance of colon cancer.

Adenoma↗
PubMed2005

Computer aided detection for low-dose CT colonography.

The paper describes a method for automatic detection of colonic polyps, robust enough to be directly applied to low-dose CT colonographic datasets. Polyps are modeled using gray level intensity profiles and extended Gaussian images. Spherical harmonic decompositions ensure an easy comparison between a polyp candidate and a set of polypoid models, found in a previously built database. The detection sensitivity and specificity values are evaluated at different dose levels. Starting from the original raw-data (acquired at 55mAs), 5 patient datasets (prone and supine scans) are reconstructed at different dose levels (down to 5mAs), using different kernel filters and slice increments. Although the image quality decreases when lowering the acquisition mAs, all polyps above 6mm are successfully detected even at 15 mAs. Accordingly the effective dose can be reduced from 4.93mSv to 1.61 mSv, without affecting detection capabilities, particularly important when thinking of population screening.

Algorithms↗
PubMed2006

Dose reduction and image quality in MDCT colonography using tube current modulation.

OBJECTIVE: The purpose of our study was to evaluate the dose reduction potential of combined online (x- and y-axes) and topogram-based (l) X-ray tube current modulation in CT colonography in a screening population. MATERIALS AND METHODS: Eighty asymptomatic individuals underwent CT colonography screening for colon polyps. A 16-MDCT scanner (Somatom Sensation 16) was used. Forty patients were examined at 120 kVp and 120 effective mAs (supine) and 40 effective mAs (prone) using online x- and y-axis tube current modulation. Another 40 patients were scanned using combined x-, y-, and z-axis tube current modulation. Individual patient radiation exposure was determined using the dose-length product. Image noise was determined by Hounsfield unit measurements in the colonic lumen at four anatomic levels. Image quality was rated on a 5-point confidence scale by two independent reviewers. The unpaired Student's t test (for radiation dose, image noise) and Wilcoxon's test (for image quality) were used to test for statistically significant differences between these values. RESULTS: Radiation dose was significantly lower in the patient group scanned with x-, y-, and z-axis tube current modulation than in the group scanned with x- and y-axis tube current modulation (supine: 4.24 vs 6.50 mSv, p < 0.0001; prone: 1.61 vs 2.38 mSv, p < 0.0001). Radiation dose was reduced by 35% (supine) and 33% (prone). No statistically significant difference was seen in overall image noise (supine: 15.9 vs 16.3 H, p = 0.13; prone: 23.5 vs 24.8 H, p = 0.44) or image quality (supine: 4.6 vs 4.5, p = 0.62; prone: 3.5 vs 3.6, p = 0.54). CONCLUSION: Combined x-, y-, and z-axis tube current modulation leads to a significant reduction of radiation exposure in CT colonography without loss of image quality.

Aged↗
PubMed1990

Colonic polyamine content and ornithine decarboxylase activity as markers for adenomas.

Polyamine content (putrescine, spermidine, and spermine) or ornithine decarboxylase (ODC) activity was measured in normal-appearing colonic mucosa from patients undergoing colonoscopy. Comparisons were made between those with and those without adenomatous polyps. Colonic mucosal polyamine content was measured in 44 persons. Mean putrescine content was 1.25 +/- 0.26 (SE) nmol/mg protein in 22 patients with adenomatous polyps compared with 0.53 +/- 0.12 nmol/mg protein in patients without polyps (P less than 0.02). Tissue content of spermidine and spermine did not differ between these two groups. Ornithine decarboxylase activity was measured in tissue from 45 patients. Mean ODC activity was 2.84 +/- 0.73 pmol/hr/mg protein in 23 persons with adenomatous polyps compared with 1.15 +/- 0.18 pmol/hr/mg protein in persons without polyps (P less than 0.05). Mucosal putrescine and ODC activity are elevated in patients with adenomatous polyps compared with patients without polyps. These biochemical markers may prove helpful in improving surveillance methods for colorectal cancer and premalignant adenomatous polyps.

Aged↗