SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Adenomatous polyps are the precursors of most colonic cancers and should be removed and recovered for histological analysis. Removal by endoscopic laser photocoagulation offers a safe alternative to surgery. We report our experience of managing selected colonic polyps by neodymium:yttrium aluminum garnet (Nd:YAG) laser.
We studied by immunocytochemistry 573 tissue and 106 cytologic samples of human tumors, non-neoplastic proliferative lesions and normal tissues with the monoclonal antibody (Mab) A-80 that recognizes a mucinous glycoprotein from the colon carcinoma cell line LS-174T. The spectrum of benign and malignant breast lesions was studied as were epithelial tumors of the colon, stomach, pancreas, lung, salivary glands, thyroid, prostate, kidney, endometrium, skin and mesothelium; non-epithelial tumors included lymphomas, melanomas, gliomas, meningiomas, and sarcomas of soft tissue and bone. With a single exception, breast carcinomas regardless of histologic type were reactive while few fibroadenomas stained weakly and focally. In fibrocystic disease, the presence and intensity of the reactivity paralleled the severity of the epithelial proliferation, e.g. staining was strong in foci of severe or atypical hyperplasia, borderline lesions and carcinomas in situ; apocrine metaplasia stained often but less strongly. Barrett's mucosa, colonic polyps and most gastric and colonic carcinomas stained regardless of glandular features while small cell neuroendocrine carcinomas did not. Adenocarcinomas of the pancreas and lung, and a subset of large cell lung carcinomas reacted whereas neuroendocrine carcinomas of those sites did not. Carcinomas of endometrium, ovary and prostate reacted variably whereas thyroid and renal carcinomas and mesotheliomas were either negative or weakly reactive despite the presence of glands. Lymphomas, skin adnexal tumors, nevi, schwannomas, melanomas, gliomas and sarcomas generally did not react but occasional A-80-positive cells were seen in rare sarcomas and meningiomas. Immunostaining patterns in cytologic specimens were similar to the aforementioned. We conclude that Mab A-80 is an excellent marker for breast carcinomas, and for certain proliferative forms of fibrocystic disease that may precede or be associated with carcinomatous transformation. In colonic, pulmonary and gastric carcinomas, staining with Mab A-80 revealed exocrine features regardless of the absence of glands whereas in renal and thyroid carcinomas and in mesotheliomas staining was focal and weak or absent irrespective of glandular features. We suggest that Mab A-80 is a very promising immunolabel for select exocrine carcinomas, and for some of the dysplasias that may precede their development; its ease of application on tissue sections and cytologic specimens should broaden its usefulness.
Under examination there were 292 patients. An analysis of results of treatment enabled the authors to conclude that surgical treatment of patients with diffuse polyposis of the colon is the method of choice. The method and volume of operations must be determined according to the involvement of the colon in polyposis, the age and state of the patients. The best method of surgery is a one-step radical operation-subtotal resection of the colon. Polyps concomitant to cancer of the colon should be ablated before the main operation since their histological analysis can change the volume of the planned radical operation. When choosing the method of surgical intervention for patients with primary-multiple cancer against the background of polyps the total portion of the colon with polyps should be ablated.
Adenomatous polyps in the adult colon and rectum are of great clinical importance because they can undergo malignant degeneration. Size and histologic type are useful in predicting the likelihood of malignancy. In most cases, biopsy is required to distinguish small adenomas (< 1 cm) from hyperplastic polyps, which do not undergo malignant degeneration. An adenomatous polyp found during proctosigmoidoscopy warrants total colonoscopy with polypectomy, because of the possibility of a synchronous adenoma or cancer. Periodic colonoscopic follow-up is advised, because of the high rate of recurrent ("metachronous") adenomas. The optimal screening technique for colorectal polyps and early cancer in the general population remains to be defined. The most commonly used program at present entails periodic fecal occult blood testing and flexible proctosigmoidoscopy. Diets high in fiber and low in fat may have protective effects against the development of colonic neoplasms.
INTRODUCTION: Complete preoperative study of the colon is required in the management of colorectal cancer, due to the frequent association of primary colonic neoplasms with colonic adenomas (28%) and/or synchronous carcinomas (5%) of the colon. We present a series of patients who underwent computed tomographic colonography, the indications for this procedure, and the results. PATIENTS AND METHODS: We performed a descriptive prospective study. Between May 2003 and August 2004, 50 computed tomographic colonographies were performed in 50 patients with suspected stenosing colorectal cancer and incomplete conventional colonoscopy. RESULTS: Fifty computed tomographic colonographies were performed. The findings were as follows: three were normal (6%), and in the remainder, one was a false positive for a suspected neoplastic pelvic mass (3.125%) and two were false positives (11.7%) for colonic polyps. Fifty percent of the findings (n = 32) were related to peritoneal metastases and colonic neoplasms. There were 12 technical complications [lack of cleaning of the colon (5), lack of distension (2), little air insufflation (5)]. Patient complications included vegetative manifestations in one (vomiting) and rectal bleeding in another. The overall complication rate was 27.4% (23.4% corresponded to technical complications and the remaining 4% were patient-related). There was no mortality related to the procedure. CONCLUSION: Because computed tomographic colonography is safe, effective and well tolerated by the patient, it should be considered as a technical alternative in the study of stenosing neoplasms of the proximal colon with incomplete colonoscopy. In addition, it allows other associated findings, both intra- and extracolonic, to be obtained and improves the diagnostic and therapeutic management of the patient.
The single-contrast barium enema examination remains useful for patients with acute diseases such as bowel obstruction, diverticulitis, appendicitis, and fistulas. It is also the procedure of choice for those patients who are too elderly, debilitated, or ill to cooperate with the maneuvers necessary for a double-contrast examination. The double-contrast technique is more sensitive than the single-contrast technique for detection of polyps, early inflammatory bowel disease, and lesions of the rectum. In the older population, there has been an increase in the incidence of colonic polyps and carcinomas in the right side of the colon. This emphasizes the need to examine the entire colon in these patients. The double-contrast barium enema is a safe, accurate, and cost-effective tool for accomplishing this. It is also recommended as the initial procedure in the examination of patients with positive results on fecal occult blood testing.
We present a novel pipeline for computer-aided detection (CAD) of colonic polyps by integrating texture and shape analysis with volume rendering and conformal colon flattening. Using our automatic method, the 3D polyp detection problem is converted into a 2D pattern recognition problem. The colon surface is first segmented and extracted from the CT data set of the patient's abdomen, which is then mapped to a 2D rectangle using conformal mapping. This flattened image is rendered using a direct volume rendering technique with a translucent electronic biopsy transfer function. The polyps are detected by a 2D clustering method on the flattened image. The false positives are further reduced by analyzing the volumetric shape and texture features. Compared with shape based methods, our method is much more efficient without the need of computing curvature and other shape parameters for the whole colon surface. The final detection results are stored in the 2D image, which can be easily incorporated into a virtual colonoscopy (VC) system to highlight the polyp locations. The extracted colon surface mesh can be used to accelerate the volumetric ray casting algorithm used to generate the VC endoscopic view. The proposed automatic CAD pipeline is incorporated into an interactive VC system, with a goal of helping radiologists detect polyps faster and with higher accuracy.
INTRODUCTION: Epidemiologic and molecular biologic studies have already demonstrated that adenomatous colonic polyps are precancerous diseases. The main indication of the colonoscopy in the surveillance of colorectal cancer treated patients is the diagnosis and resection of adenomatous polyps. AIM: To study the frequency of adenomatous polyps after surgically resection of colorectal cancer. MATERIAL AND METHODS: Sixty eight patients, mean age 59 years old, with total resection of colorectal cancer, submitted to various colonoscopies during the follow up were studied retrospectively. The histological type and the characteristics of the polyp were described. RESULTS: The frequency of polyps was 18%, being higher in the patients with more than 45 years (20%). The site of the polyps was in the left colon in 38% of the patients with cancer. The histological type of adenomas was tubular in 61%, villous in 22% and mixed in 17%. DISCUSSION: As described by other authors, the incidence of polyps were higher after 45 years old and more than a half of them were tubular. The frequency of polyps was higher in the first two years of follow up.
BACKGROUND: Epithelial tumors of the papilla of Vater are rare neoplasms of the gastrointestinal tract. The carcinogenesis of these tumors seems to be fairly analogous to the genetic mechanisms which have been described for colorectal carcinoma. Patients with familial adenomatous polyposis bear a particularly increased risk for periampullary tumors. Data on whether the prevalence of colorectal tumors is increased in patients with sporadic ampullary neoplasms are scarce. METHODS: 26 consecutive patients (16 women, 10 men; median age 59 years) with sporadic adenomas (n = 19) or adenocarcinomas (n = 7) of the ampulla of Vater were retrospectively evaluated. The study patients were compared with 104 age-matched asymptomatic controls. All patients had undergone total colonoscopy. RESULTS: Neoplastic colorectal polyps were present in a similar proportion (23%) of patients of the study group compared with 26% in the control group (p > 0.05). Overall, 16 polyps were found among patients with ampullary tumors and 40 in asymptomatic controls (p > 0.05). Colonoscopy detected rectal carcinoma in 2 patients (8%) of the study group. Patients with and without colorectal polyps differed neither significantly by age nor by ampullary histological findings. 50% of the colonic polyps in patients with ampullary neoplasms were located in the ascending colon. CONCLUSIONS: The frequency of colorectal polyps in patients with ampullary tumors did not exceed the risk in the control group. However, the finding of 2 rectal carcinomas among patients with ampullary neoplasms supports the place of screening colonoscopy for the diagnostic work-up of ampullary tumors. Prospective multicenter studies should address this issue to provide a broad basis for future recommendations.
With the aid of colon-polyp phantoms, basal indentation (BI) of polypoid lesions on double-contrast examinations of the colon was studied. Our findings indicated that BI is a function of radio-geometric projections and its morphology (arcuate, angular and trapezoid) depends on size, shape and surface pattern of a polypoid lesion. These findings were also substantiated by specimen and clinical radiography.
BACKGROUND AND AIMS: Colonoscopy is the best available method to detect and remove colonic polyps and therefore serves as the gold standard for less invasive tests such as virtual colonoscopy. Although gastroenterologists agree that colonoscopy is not infallible, there is no clarity on the numbers and rates of missed polyps. The purpose of this systematic review was to obtain summary estimates of the polyp miss rate as determined by tandem colonoscopy. METHODS: An extensive search was performed within PUBMED, EMBASE, and the Cochrane Library databases to identify studies in which patients had undergone two same-day colonoscopies with polypectomy. Random effects models based on the binomial distribution were used to calculate pooled estimates of miss rates. RESULTS: Six studies with a total of 465 patients could be included. The pooled miss rate for polyps of any size was 22% (95% CI: 19-26%; 370/1,650 polyps). Adenoma miss rate by size was, respectively, 2.1% (95% CI: 0.3-7.3%; 2/96 adenomas > or =10 mm), 13% (95% CI: 8.0-18%; 16/124 adenomas 5-10 mm), and 26% (95% CI: 27-35%; 151/587 adenomas 1-5 mm). Three studies reported data on nonadenomatous polyps: zero of eight nonadenomatous polyps > or =10 mm were missed (0%; 95% CI: 0-36.9%) and 83 of 384 nonadenomatous polyps <10 mm were missed (22%; 95% CI: 18-26%). CONCLUSIONS: Colonoscopy rarely misses polyps > or =10 mm, but the miss rate increases significantly in smaller sized polyps. The available evidence is based on a small number of studies with heterogeneous study designs and inclusion criteria.
PURPOSE: To evaluate two key processing steps for detection of colon polyps with spiral computed tomographic (CT) colography with perspective volume rendering (PVR): image reconstruction and opacity assignment of the attenuation data. MATERIALS AND METHODS: Spiral CT was performed in 10 patients with known polyps confirmed at colonoscopy, and detailed quantitative analyses were performed of data obtained in four. First, anatomic fidelity of three-dimensional (3D) images generated from two-dimensional (2D) source images with equal voxel dimensions (87%-90% overlap) was compared with 3D images generated from 2D source images with unequal voxel dimensions (0%-80% overlap). Next, the relative dimensions of colorectal polyps to adjacent structures were evaluated for various opacity threshold settings. Then, step and sigmoidal opacity functions were compared with respect to image smoothness and edge sharpness. RESULTS: PVR images generated after interpolation of image data reconstructed with at least 60% overlap were equivalent in image quality to PVR images generated from source images with equal voxel dimensions. Relative polyp-to-haustral fold dimensions demonstrated substantial distortions with opacity thresholds below -700 HU. The 3D PVR images generated with the sigmoidal opacity function were significantly smoother than those generated with the step opacity function (paired t test, P < .02), with small differences noted in edge sharpness. CONCLUSION: Use of highly overlapping source images (87%-90%) was not necessary to generate 3D PVR images of colorectal polyps. Image artifacts were suppressed with use of an appropriate opacity threshold and a sigmoidal opacity function without substantial loss in edge sharpness.
The paper describes methods used for an interactive real-time training simulation of an endoscopic procedure: the removal of a colon polyp. Biomechanical simulation of the polyp is provided by a Finite Element approach. A combination of animation and simulation models the flexing, retraction and deployment of the used instrument, a wire sling. The presented method enables a training simulation of the surgery, based on the endoscopic simulator EndoSim.
After presenting a classification of colon polyps the author comments on a follow-up group of 200 patients. Only genuine tumours have been taken into consideration. The rate of malignant degeneration is very high. Each determined polyp has to be removed totally to achieve prophylaxis. Postoperative control of the patients is an imperative demand for their lifetime.
BACKGROUND: Inheritance is important to the development of colonic adenomatous polyps and colon cancer. Current knowledge of inherited susceptibility to colonic neoplasms suggests that colon cancer screening strategies should consider familial and genetic risk. METHODS: This report reviews the literature pertinent to adenomatous polyp and colon cancer inheritance and suggests polyp-cancer screening procedures based on inherited or familial risk. RESULTS: Colorectal adenomas and cancer occur in several rare inherited syndromes and more commonly as sporadic cases. Intensive screening protocols have been suggested for the inherited syndromes because of the high associated cancer risk. Recent evidence suggests that inherited susceptibility also may be important in a large fraction of the so-called sporadic cases. Preliminary screening guidelines are suggested for this category based on the number of first-degree relatives affected with colon cancer. CONCLUSIONS: Inherited susceptibility appears to be more important to the pathogenesis of colorectal adenomas and cancer than previously recognized. Screening strategies which consider inherited risk may increase the effectiveness of cancer detection and prevention.
A group of 531 participants age 50 years or older were evaluated for colonic polyps and malignancy with stool occult blood testing, hemoglobin, hematocrit, serum ferritin, flexible fiberoptic sigmoidoscopy, and colonoscopy. Screening revealed 1 colorectal cancer, 2 malignant polyps, 30 hyperplastic polyps, 69 adenomatous polyps, 4 villous adenomas, and 2 villous components. Low serum ferritin, an indicator of iron deficiency without anemia, improved the detection of colonic malignancies and polyps when used in combination with stool occult blood testing. The program was acceptable to participants and attrition was low; the attrition rate for the screening program at 1 year was 14.5%.
Explore the source record for details and available documents.
BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) (the Osler-Weber-Rendu syndrome) is a rare autosomal dominant disease characterized by telangiectasias and arteriovenous malformations of the upper and lower respiratory tract, gastrointestinal tract, skin and central nervous system. Several previous reports have documented the appearance of a concomitant neoplasm in patients with this syndrome. AIMS: To study the occurrence and the clinical characterization of colonic neoplasm in patients with HHT. METHODS: We retrospectively reviewed the computerized database of the Hadassah University Hospitals (Jerusalem, Israel) for all patients with the diagnosis of HHT between January 1st, 1980 and July 30th, 2002. Cases of neoplasm were documented by review of medical charts and pathology reports. RESULTS: Six of the 24 patients developed malignancy. Three of the cases had extra colonic malignancy (melanoma in two patients and adenocarcinoma of urinary bladder in one patient) and three patients had adenocarcinoma of the colon. An additional three patients developed multiple colonic polyps (one patient had melanoma and one patient had adenocarcinoma of urinary bladder). CONCLUSIONS: HHT may be associated with the development of colonic adenocarcinoma and polyps. Therefore, in patients with HHT who present with new-onset anemia or gastrointestinal bleeding a lower gastrointestinal tract evaluation should be performed, even if their blood loss is suspected to be a manifestation of gastrointestinal HHT.