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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Colonoscopy is a valuable and frequently used method in the evaluation of colonic neoplasia. Flow cytometry is a technique that can be used to diagnose malignancy. In this study, flow cytometry was used to evaluate colonoscopic biopsies taken from patients with suspected colonic neoplasia. Nineteen colonic biopsies were obtained and evaluated by this technique. Aneuploidy was demonstrated in six patients with carcinoma of the colon. In addition, abnormal DNA histograms were noted in two premalignant conditions (colonic adenoma and inflammatory bowel disease). The results show that flow cytometry can be applied to colonic biopsies and suggest that it may be of use in the diagnosis of malignant and premalignant conditions of the colon.
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PMID:Evaluation of colonic neoplasia by flow cytometry of endoscopic biopsies. 396 54

Using an in vitro double labeling technique with two different levels of 3H-thymidine, the duration of the phase of DNA synthesis (S) and the labeling index (LI) were measured in the colorectal mucosa of three groups of patients: patients with colorectal neoplasms (adenomas and/or adenocarcinomas), patients with inflammatory bowel disease, and a control group of patients without gastrointestinal pathology. In those patients with colorectal neoplasms, samples were obtained from both the neoplastic mucosa and from the normal appearing mucosa at various distances from the lesions. One-way analyses of variance were used to test the equality of mean S-phase duration and LI in the various types of tissues. S-phase duration was significantly longer in the tumor than in the unaffected mucosa of patients with adenocarcinoma (18.65 hours +/- 2.3 versus 10.13 hours +/- 1.26 P less than 0.0001). However, S-phase duration was significantly longer in the unaffected mucosa of cancer patients than in the mucosa of patients without gastrointestinal pathology (10.58 hours +/- 1.84 versus 7.91 hours +/- 0.46, P = 0.013). Similarly, LI was significantly higher in the unaffected mucosa of patients with adenoma and adenocarcinoma than in the mucosa of patients without gastrointestinal pathology (19.1% +/- 3.0 versus 9.5% +/- 2.2, P less than 0.0001). There was a highly significant trend to a progressive increase of LI from flat histologically normal appearing mucosas to inflammatory mucosas, adenomas, and adenocarcinomas (P less than 0.0001). These results suggest that increased S-phase duration is specifically related to cancer. In mucosa without histologic sign of malignancy, an increased S-phase duration would indicate that the malignant process has started. An increased LI would appear to relate to the selective advantage that rapidly proliferating cells hold over less proliferating ones.
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PMID:Cell kinetic indicators of premalignant stages of colorectal cancer. 400 81

Two hundred and twenty seven patients had multiple follow-up total colonoscopies after initial endoscopic polypectomy. All adenomas were removed at the initial examination ('clean colon') in those patients who had no history of colon cancer, inflammatory bowel disease or polyposis coli; when re-endoscoped within one year 56% of them were found to have further adenomas. Nine percent had adenomas over 10 mm diameter which are presumed to have been missed during the index colonoscopy. Patients with single or multiple adenomas had an equal likelihood of being found to have further lesions on a one-year follow-up colonoscopy. With an apparent chance of missing a significant-size polyp at colonoscopy of at least 10% we recommend that all patients have a follow-up colonoscopy within one year after polypectomy. 133 Patients in whom no adenomas were found at the one year colonoscopy ('negative colonoscopy') were followed up. The incidence of new adenomas occurring within four years of 'negative colonoscopy' was 35% for those with a single adenoma at the index examination and twice as high for patients with multiple adenomas. If no polyp is found at one year, we recommend that interval follow-up colonoscopies should be performed every two years if more than one adenoma was removed during the initial examination, and every three years if only one was removed.
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PMID:Surveillance intervals after colonoscopic polypectomy. 707 64

Flat adenomas have been reported to be associated with an increased risk of high grade dysplasia and with a genetic predisposition to numerous colonic polyps. Histological findings reported for flat adenomas are dysplastic glands superficial to nondysplastic glands and a thickness of dysplastic mucosa that does not exceed twice that of nondysplastic mucosa. We assessed the specificity of these histological findings with regard to a colonoscopically flat appearance in a series of 127 sequentially accessioned adenomas from 52 patients without adenomatous polyposis coli or inflammatory bowel disease. Thirty-two of the 127 adenomas (25%) from 20 of 52 patients (36%) showed the histological findings outlined above; none of these polyps was grossly flat and none had high grade dysplasia. The predictive values of these histological features for patients younger than 50 years old and for the presence of five or more polyps in a patient were 15% and 25%, respectively. We conclude that the histological findings previously reported for flat adenomas are not specific for that entity and are not uncommonly seen in grossly typical appearing adenomatous polyps. These histological findings also are not associated with high grade dysplasia. They can be seen in polyps from individuals without clinically recognized polyposis, and are relatively poor indicators of young age or increased polyp number, features that could potentially indicate a clinically unrecognized polyposis syndrome. The histological findings in and of themselves thus appear to confer no additional cancer risk to the individual or to the individual's family members over and above that associated with an adenoma.
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PMID:The nonspecificity of histological findings reported for flat adenomas. 775 Sep 41

The control of colorectal cancer is currently dependent on early detection, and its prevention requires the recognition and treatment of its precursor lesions. The adenoma has been established as the precursor of colorectal carcinoma in the general population. Among patients with inflammatory bowel disease (IBD), dysplasia is associated with, and precedes, invasive carcinoma. In this section criteria are described for the histological detection of preinvasive and early invasive neoplasia in the large intestine of patients with and without IBD. The therapeutic implications of these diagnoses are stressed. A brief review of subcellular changes, including genetic alterations, in colorectal neoplasia is included.
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PMID:Dysplasia and early carcinoma in inflammatory bowel disease and colorectal adenomas. 795 60

Colonoscopy is the initial examination for patients with manifest or occult rectal bleeding, inflammatory bowel disease and colorectal polyps. In addition to polypectomy, colonoscopy is useful in decompression of adynamic colonileus and laser palliation of intractable tumours. In adenoma patients controls should be limited to high risk patients, i.e. those with large and multiple tubular adenomas, villous adenomas, multiple hyperplastic polyps (> 30), and first degree relatives of patients with colorectal carcinomas. Control after radical surgical treatment of colorectal cancer is offered during the first two years after the operation and to persons younger than 40 years. The efficacy of control programmes for hereditary nonpolyposis colorectal cancer families have to be evaluated in controlled series. Rectosigmoidoscopies could probably replace some total colonoscopies to examine ulcerative colitis patients for cancer, since cancer usually occurs in the distal colon. Complications are rare after diagnostic and therapeutic colonoscopies, but perforation, bleeding and injury to surrounding organs can be experienced.
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PMID:[Colonoscopy. In investigation, treatment and control of gastrointestinal diseases]. 798 74

Surgery is the mainstay of therapy for colon and rectal cancer. Over the past several decades, there have been important advances both in the understanding of the biology of colon and rectal cancer and in the preoperative and operative techniques for treating this disease. Although it appears in some studies that we have made a difference in the survival rates in the treatment of colon and rectal cancer, in actual fact, this phenomenon may only be secondary to better staging and, therefore, a greater ability to prognosticate a particular patient's chance of cure. What has been learned in the past 20 to 30 years is that most colon and rectal carcinomas start as polyps of the colon and rectum. Most often, polyps are sporadic, but there are certain high-risk groups that produce polyps and, consequently, colon and rectal cancer at a much higher rate. The goal of a practicing physician is to identify these high-risk individuals and to recommend frequent screenings so as to intervene before a polyp has had a chance to become a deeply invasive cancer. These high-risk groups are best typified by familial adenomatous polyposis, which if left untreated will, in 100% of cases, lead to the death of a patient from colon or rectal cancer. Other diseases that lead to an increase in colon and rectal cancer but may not go through the usual adenoma-to-carcinoma sequence include inflammatory bowel disease such as Crohn's colitis and ulcerative colitis. Most patients with colorectal carcinoma are asymptomatic at the time of diagnosis. This phenomenon has led to efforts to screen the general population for polyps and for cancer. Screening techniques such as the detection of occult blood in the stool and endoscopic procedures are currently the most popular. It is unclear at this time exactly what the efficacy of these techniques is in improving the survival of the general population from colorectal carcinoma. The surgical techniques to remove colon and rectal carcinomas have recently expanded to include a more aggressive local excision policy for small tumors of the rectum and the application of laparoscopic techniques, new stapling techniques, and new anastomosing techniques for tumors of the colon and rectum. These techniques have become possible in part through advances in surgical instrumentation and also in part from our increasing understanding of the biology of the disease. Both have allowed for more creative approaches to diagnosing and treating colon and rectal cancer.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Recent advances in surgery for colon and rectal cancer. 851 79

Events of reproductive life, such as parity and age at menarche, have been found in some but not all studies to be associated with risk for colorectal cancer in females. Because adenomatous polyps (adenomas) are precursors of colorectal cancer, we investigated whether reproductive variables were associated with colorectal adenomas. We conducted a case-control study among patients examined in three colonoscopy practices in New York City (NY, United States) from 1986 to 1988. Adenoma cases (n = 128) were defined as women who had an adenoma detected at the index colonoscopy with no history of inflammatory bowel disease, adenomas, or cancer. Controls (n = 283) were women with a normal index colonoscopy and no history of inflammatory bowel disease, adenomas, or cancer. The adjusted odds ratio (OR) for the association of early menarche (age less than 13 years) with adenomas was 0.6 (95 percent confidence interval = 0.4-0.9). Parity, history of spontaneous or induced abortion, infertility, type of menopause, age at menopause, use of oral contraceptives, and use of menopausal hormone replacement therapy were not associated statistically significantly with adenoma risk, although some possible trends were observed. Our findings do not implicate reproductive events, nulliparity, or overexposure to estrogens or to menstrual cycles as mechanisms of increased risk for colorectal neoplasia.
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PMID:Reproductive risk factors for colorectal adenomatous polyps (New York City, NY, United States). 858 Feb 99

Over a 4-year period, a direct-access fibreoptic sigmoidoscopy service was evaluated prospectively. In all, 756 patients were referred (median age 58 years, range 18-91 years). The principal indications were rectal bleeding (45%) or change of bowel habit (28%); both features were present in 13%. Abnormalities were present in 68% of examinations. Major disease was identified in 22% (carcinoma 7.0%, adenoma 6.3%, inflammatory bowel disease 8.3%) and minor disease in 53% (haemorrhoids 36.8%, severe diverticular disease 10.9%, non-adenomatous polyp 3.4%, perianal disease 1.4%). In patients under 40 years of age, major disease was rare (one carcinoma, three adenomas). Of the patients, 21% underwent barium enema for incomplete examination or suspected additional disease. No additional major disease was identified, but one carcinoma found in a patient with stricture. These data show that a direct-access fibreoptic sigmoidoscopy service produces a high diagnostic yield and may be of value to both patients and general practitioners in expediting a clinical colorectal service.
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PMID:Four-year evaluation of a direct-access fibreoptic sigmoidoscopy service. 871 66

Arginase activity of the intestinal mucosa was tested as a proliferative marker in the adenoma-carcinoma sequence. The enzyme activity was determined by an end-point colorimetric method with L-arginine as substrate. Arginase activity was evaluated in 430 biopsy samples of large bowel mucosa, polyps and cancer tissue. The activities (U/g protein, mean +/- SE; n) were: normal mucosa 83.2 +/- 7.3; 25, adenomas 199.4 +/- 19.1; 40, carcinomas 1269.7 +/- 174.9; 40, inflammatory bowel disease 1210.7 +/- 247.1; 34. The arginase activity differs significantly in the adenoma-carcinoma sequence according to the Duncan's test (p < 0.05).
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PMID:Arginase activity determination. A marker of large bowel mucosa proliferation. 887 37


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