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PubMed2003

Laparoscopic treatment of colonic polyps. A review.

Laparoscopy is now utilized to surgically treat a wide variety of intra-abdominal disorders and an increasing number of colorectal procedures can be performed with these techniques. Laparoscopic surgery for colorectal disorders has gained increased popularity among many general and colorectal surgeons. The advantages of laparoscopic and laparoscopic assisted segmental resection for endoscopically irretrievable colonic polyps seems evident. Potential advantages include increased pain, decreased length of ileus, hospitalization, and ultimately cost, improved cosmesis, and in the longer term, potentially decreased adhesions and bowel obstructions due to adhesions. These goals can be achieved while still performing an oncologically appropriate operation. However, it is unclear as to whether invasive malignant polyps can be adequately treated using laparoscopic techniques. As the current generation of surgical trainees employ laparoscopic techniques for a variety of intraabdominal conditions, this method may become favored for managing endoscopically irretrievable polyps. In this article, we will discuss techniques and review the published data for the laparoscopic excision of colonic polyps.

Adenoma↗

PubMed1989

[Primary carcinoma of the jejunum combined with colon polyp--report of a case].

A 47-year-old female patient with a primary carcinoma of the jejunum combined with colon polyp is presented. Having had an attack of vomiting, she visited our hospital. Oral small intestine radiography revealed a localized stricture with ulceration in the jejunum. Small intestinal endoscopy showed a tumor with an irregular surface and hemorrhagic ulceration. Selective superior mesenteric arteriography revealed a stenosis and deviation of arteries. These findings strongly indicated cancer of the jejunum, and a barium enema study and a colonoscopic examination revealed a polyp in the ascending colon. The resected tumor was histologically diagnosed as a well differentiated adenocarcinoma. CEA-positive cells also were observed. Further, a polypoid lesion in the colon was histologically diagnosed as an adenoma.

Adenocarcinoma↗

PubMed2000

Increased levels of promutagenic etheno-DNA adducts in colonic polyps of FAP patients.

Nonsteroidal anti-inflammatory drugs (NSAIDs) can regress adenomas in patients with familial adenomatous polyposis (FAP), and the mechanism involves inhibition of cyclooxygenases (COX). Reactive intermediates formed during the arachidonic acid cascade, notably by COX-2, which is upregulated in polyps of FAP patients, may promote various stages of the polyp --> adenoma --> carcinoma sequence. Etheno-DNA adducts can be derived from reactive intermediates generated during arachidonic acid metabolism and lipid peroxidation. We tested this hypothesis in colonic polyps from FAP patients and colorectal tissue from cancer patients to see whether increased formation of etheno-DNA adducts occurs. Using an ultra-sensitive and specific immunoaffinity/(32)P-postlabelling method, 1, N(6)-ethenodeoxyadenosine (straightepsilondA) and 3, N(4)-ethenodeoxycytidine (straightepsilondC) were quantitated in epithelial cell DNA from asymptomatic colon, FAP polyps and colon tumor tissues. Mean adduct levels in FAP polyps were 65 straightepsilondA/10(9) and 59 straightepsilondC/10(9) parent nucleotides, being 2 to 3 times higher than in unaffected colon tissue (p < 0.02 for straightepsilondA; p < 0.05 for straightepsilondC). Adduct levels in colonic epithelia decreased in the order: FAP polyps > tumor-adjacent tissue > tumor, normal and tumor-distal tissue. Based on this study, requiring confirmation in a larger number of patients and in experimental models, we have demonstrated the formation of promutagenic etheno-DNA adducts in adenomatous polyps of FAP patients that may contribute to genetic instability and cancer progression.

Adenoma↗

PubMed1989

Spatial clustering of multiple hyperplastic, adenomatous, and malignant colonic polyps in individual patients.

Analysis of relative polyp locations in 426 consecutive patients with multiple colonic polyps found on colonoscopy showed novel findings. First, synchronous and metachronous neoplastic polyps showed spatial clustering in individual patients. For example, patients with their largest neoplasm in the cecum or proximal ascending colon, had 34.3 percent +/- 4.6 percent (standard error) of their other colonic neoplasms in the same location. Second, hyperplastic polyps showed spatial clustering in individuals that was statistically significantly greater than expected from the increased hyperplastic polyp concentration in the rectum and sigmoid. Third, hyperplastic polyps showed spatial clustering with neoplastic polyps; this clustering was similar in magnitude to clustering for exclusively hyperplastic or neoplastic polyps. In contrast, lipomas were not spatially clustered with hyperplastic and neoplastic polyps. The magnitude of clustering between hyperplasia and neoplasia showed a closer association between these histologic types than previously appreciated. Because of clustering, regions with prior polyps appear to merit closer surveillance. These findings suggest clinical study, using a randomized controlled clinical trial, of whether a patient who had only rectal and sigmoid adenomas on initial and follow-up colonoscopy should have surveillance with flexible sigmoidoscopy alternating annually with colonoscopy. A patient with a prior cecal adenoma should have surveillance only with a complete colonoscopy or adequate cecal views on barium enema.

Adenoma↗

PubMed1995

Diminutive colonic polyps: histopathology, spatial distribution, concomitant significant lesions, and treatment complications.

OBJECTIVES: Our objectives in this study were to determine diminutive colonic polyp histology, distribution, frequency of significant synchronous neoplastic lesions, and treatment complications. METHODS: We evaluated consecutive colonoscopic examinations in which one or more diminutive polyps were detected over a 36-month period; these examinations had been entered into an endoscopy database at the time of colonoscopy. RESULTS: A total of 1964 diminutive polyps were found and removed in 753 colonoscopies; 1525 were removed by hot biopsy, 436 were removed by cold biopsy, and three were removed by snare. Of the diminutive polyps, 40.7% were adenomatous, 37.2% were hyperplastic, 17.9% were mucosal tags or lymphoid aggregates, and 4.3% were mixed; 0.26% contained atypia, and none were cancerous. In the right colon and transverse colon, diminutive polyps were more likely to be neoplastic (p < 0.0001), but in the left colon they were more likely to be nonneoplastic (p < 0.0001). The prevalence of synchronous neoplastic lesions was 21.5%. No perforations were seen; however, significant hemorrhages occurred in six cases in which hot biopsy was used. The risk of a significant hemorrhage from hot biopsy of diminutive polyps was 0.39%. The risk of hot biopsy-induced hemorrhage was significantly higher in the right colon than in the transverse colon and left colon (p < 0.05). The risk in the cecum was 1.33%; in the ascending colon it was 1.03%, and for the remainder of the colon it was 0.24%. CONCLUSIONS: Most diminutive polyps proximal to the left colon are neoplastic. The decision to use the hot biopsy or cold biopsy technique to eradicate diminutive polyps should take into account the location of the polyp because of the significantly increased risk of hemorrhage with hot biopsies in the right colon.

Adenoma↗

PubMed2003

Computer-assisted detection of colonic polyps with CT colonography using neural networks and binary classification trees.

Detection of colonic polyps in CT colonography is problematic due to complexities of polyp shape and the surface of the normal colon. Published results indicate the feasibility of computer-aided detection of polyps but better classifiers are needed to improve specificity. In this paper we compare the classification results of two approaches: neural networks and recursive binary trees. As our starting point we collect surface geometry information from three-dimensional reconstruction of the colon, followed by a filter based on selected variables such as region density, Gaussian and average curvature and sphericity. The filter returns sites that are candidate polyps, based on earlier work using detection thresholds, to which the neural nets or the binary trees are applied. A data set of 39 polyps from 3 to 25 mm in size was used in our investigation. For both neural net and binary trees we use tenfold cross-validation to better estimate the true error rates. The backpropagation neural net with one hidden layer trained with Levenberg-Marquardt algorithm achieved the best results: sensitivity 90% and specificity 95% with 16 false positives per study.

Algorithms↗

PubMed2006

Poor correlation between clinical impression, the small colonic polyp and their neoplastic risk.

BACKGROUND AND OBJECTIVES: Significance of the small colonic polyp is unclear and its removal is frequently determined by the proceduralist's clinical impression. Our aims were to determine if clinical discernment is accurate, and the likelihood that lesions < 10 mm are histologically advanced. METHOD: We prospectively collected 1988 lesions from 854 subjects (2215 consecutive colonoscopies). Lesion size, location, patient age, sex and the colonoscopist's clinical impression was recorded. RESULTS: Clinical assessment for neoplasia had a sensitivity of 87.4%, specificity of 65.0%, positive predictive value of 76.0% and negative predictive value of 80.2%, resulting in an accuracy of 73.4%. Factors predictive of correct clinical impression were polyp size, location in the rectum and being pedunculated, but not the patient's age, sex or the endoscopist's experience. Of the 1434 lesions < or = 5 mm in size, 44.5% were neoplastic and 3.5% were histologically advanced. Of the 266 lesions 6-9 mm, 79.3% were neoplastic, 19.9% were histologically advanced, five demonstrated high-grade dysplasia and three were malignant. Only two patients with an adenocarcinoma or high-grade dysplasia in a polyp <10 mm had a lesion > or =10 mm elsewhere in the colon. Of the 288 lesions > or =10 mm in size, 92.7% were neoplastic, 29.5% had a villous component, 6.9% demonstrated high-grade dysplasia and 29.2% were malignant. Factors predictive of neoplasia were patient age, polyp size and sessile nature of the lesion. CONCLUSION: Polyps < 10 mm had a significant risk of neoplasia and advanced histology and, in general, clinical impression correlated poorly with neoplasia. Removal of all lesions proximal to the rectum, regardless of size, should therefore be considered.

Adenocarcinoma↗

PubMed2000

Chronic daily low dose of 4-methyl-5-(2-pyrazinyl)-1,2-dithiole-3-thione (Oltipraz) in patients with previously resected colon polyps and first degree female relatives of breast cancer patients.

The chemoprevention agent oltipraz, one of the most active chemopreventive compounds in preclinical studies, has been shown to induce glutathione-S-transferase (GST) activity in animals. Oltipraz was evaluated in a Phase I trial at daily oral doses of 20 mg (L1), 50 mg (L2), and 100 mg (L3) and twice weekly doses of 125 mg (L4) taken for 6 months with 6 patients entered at L1 and L2 and 7 patients entered at L3 and L4 (26 subjects: 19 females and 7 males). The subject population included patients with previously resected colon polyps and first-degree female relatives of breast cancer patients. Patients with resected colon polyps underwent rectal biopsy for GST and glutathione (GSH) analyses. Of the 26 subjects, the following completed 6 months of therapy: 4 of 6 patients (L1), 4 of 6 patients (L2), 5 of 7 patients (L3), and 4 of 7 patients (L4). Toxicities were mild to severe and included: gastrointestinal symptoms, photosensitivity/heat intolerance, and neurological symptoms. Monthly plasma samples were obtained 2-3 h after oltipraz ingestion with minimally detectable plasma concentrations at L1. There was a significant difference in mean oltipraz concentration across the four doses, with no significant differences in mean oltipraz concentration over time. Rectal tissue and lymphocyte GSH and GST were variable, with no significant difference in mean levels across doses. At the 100-mg/day dose (L3), 1 patient experienced significant increase in rectal tissue GSH and GST activity, whereas 3 additional patients (L1 and L4) had >50% increase in tissue GSH. Lymphocyte GSH level was significantly related to plasma oltipraz concentration. There were no significant correlations between plasma oltipraz concentration and lymphocyte GST level nor any significant correlation between plasma concentration and percentage of change in tissue GSH or GST. Further investigation of dose/schedule and biological end points is ongoing.

Anticarcinogenic Agents↗

PubMed1990

A clinico-pathological profile of colonic polyps in Brunei Darussalam--a study of 25 cases treated by colonoscopic polypectomy.

Colonic polyps are not rare in Brunei Darussalam with an incidence of 13% in 193 colonoscopies performed over the last two years. Majority of the polyps were adenomatous. Incidence was higher in the Malays and had a male preponderance. Commonest age of presentation was above the age of 40 years and the pattern is comparable to the Western pattern. All the polyps were removed by colonoscopic polypectomy.

Adenocarcinoma↗

PubMed2001

Endoscopic mucosal resection of colon polyps.

The term submucosal injection polypectomy (SIP) more accurately describes the technique used for removal of flat colonic polyps and is preferred, in the colon, to endoscopic mucosal resection (a procedure that usually uses a special suction-activated device). Using SIP, most polyps can be removed safely from any part of the colon. The methodology is described in detail and is within the capability of most colonoscopists.

Colonic Neoplasms↗

PubMed1996

Enzymes in intestinal juice from patients with liver diseases and colon polyps: measurement of bilirubin, alkaline phosphatase, aspartate aminotransferase and lactate dehydrogenase.

Since the amounts of hepatogenous enzymes discharged into the intestinal tract remain unknown, this study was initiated to evaluate the amounts of the enzymes in the intestinal tract. Whole gut lavage fluid (polyethyleneglycol electrolyte solution) was administered orally to 42 subjects, consisting of 5 patients with hepatoma, 10 with chronic hepatitis, 10 with colon polyps, and 17 control subjects without liver disease. Two hr after the large intestinal lavage, the digestive tract juice was aspirated by colonoscopy, and the bilirubin (Bil), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) in the aspirates were measured. A positive correlation between the AST and LDH values was found, and a significant difference in these values between the hepatic disorders and the normal controls was noticed. A significant positive correlation between the ALP and Bil values was found, and a statistical difference in these values between the group of colon polyps and the controls and other groups was observed. This lavage fluid technique enables to estimate the amounts of hepatic enzymes discharged into the intestinal tract, thereby opening a new avenue for future enzyme research.

Adult↗

PubMed2002

Step section histology of proximal colon polyps that appear hyperplastic by endoscopy.

OBJECTIVE: Recent studies have identified a group of polyps, usually located in the proximal colon, with distinct endoscopic features that predict hyperplastic histology. These polyps may occasionally have foci of dysplastic (adenomatous) tissue. We aimed to define the prevalence of adenomatous foci in these polyps. METHODS: Fifty-one consecutive hyperplastic-appearing proximal colon polyps were sectioned at 1-mm intervals for histological analysis. RESULTS: All 51 polyps were hyperplastic, but two (4%) had foci of adenomatous tissue. CONCLUSION: The prevalence of adenomatous foci in proximal colon polyps with endoscopic features of hyperplastic polyps is low. Whether endoscopic resection of polyps with these features is warranted remains uncertain.

Adenoma↗

PubMed1991

An appraisal of small and diminutive colonic polyps.

A retrospective review of all colonoscopic polypectomies performed in a busy surgical endoscopy unit over a 6-month period was undertaken. All patients were included who presented with colonic polyps measuring less than 1 cm in diameter for which sufficient specimens were available for histopathologic examination. In all, 262 were polyps removed from 206 patients; of these, 158 (60%) were neoplastic. There was a statistically significant predilection for polyps in the right colon to be neoplastic. Worrisome histologic patterns (severe dysplasia, carcinoma in situ, or invasive carcinoma) were seen in 18 specimens (6.5%). In two patients, polypoid carcinoma could be identified; in one case it involved a lesion measuring 0.2 cm in diameter. Since these lesions exhibit no distinctive gross features, only their endoscopic removal and histologic study can ensure proper diagnosis and treatment.

Adult↗

PubMed1997

Colonoscopic resection of large colonic polyps--a prospective study.

Forty-five patients who were referred for surgical resection of large colonic polyps after index colonoscopy were considered for endoscopic polypectomy. Eighteen of these patients were ultimately referred for surgery. Twenty-five patients with 25 large polyps underwent endoscopic polypectomy; there were 9 females and 16 males with a mean age of 69 years. Among the polypectomy patients, polyp size was 3.0-6.0 cm, found mostly in the left colon. There were 21 pedunculated and 4 sessile polyps. Follow-up was carried out for a mean of 48 months (range, 12-171 months). Polypectomy was possible on a single attempt in 12 (48%) cases and in 13 (52%) cases by a piecemeal technique. Pathological examination revealed malignancy in 11 (44%), adenomatous polyp in 11 (44%), and inflammatory, hyperplastic and harmartoma in 1 patient each. Complications included bleeding in 3 (12%) patients and diarrhea and fever in 1 (4%). All complications were successfully treated conservatively without sequellae. Two patients were referred for surgery, 1 with invasion of the base of the polyp and 1 because of a synchronous malignant polyp. During follow-up, 8 metachronous polyps were detected. In 1 of these, a carcinoma was found and treated with endoscopic polypectomy. In conclusion, endoscopic polypectomy of large polyps is safe and can defer surgical treatment. Regular follow-up is required. Endoscopic polypectomy of large polyps should be considered before referral for surgical treatment.

Adenomatous Polyps↗

PubMed1984

Mucosal ganglioneuromatosis associated with multiple colonic polyps.

Two unusual cases of colonic ganglioneuromatosis are described. One case was associated with multiple adenomatous polyps in a 74-year-old man and the second case was associated with juvenile polyps in a 16-year-old boy. To our knowledge this is the first report of colonic mucosal ganglioneuromatosis associated with multiple adenomatous polyps and the second report associated with multiple juvenile polyps. In the first case the ganglioneuromatosis was found in colonic mucosa without adenomatous changes, while in the second case ganglioneuromatosis was found both within normal mucosa and within juvenile polyps. The relationship between mucosal ganglioneuromatosis and multiple colonic polyps remains unclear. Neither patient has yet developed features to suggest either multiple endocrine neoplasia type 2b or von Recklinghausen's disease.

Adolescent↗

PubMedDate not supplied

Cronkhite-Canada syndrome with adenomatous and carcinomatous transformation of colonic polyp.

We describe a 70-year-old woman who presented with watery diarrhea and was found to have gastric and colonic polyposis, cutaneous hyperpigmentation, alopecia and onychodystrophy (Cronkhite-Canada syndrome). Histology of a polyp from the stomach showed features of juvenile or retention type (hamartomatous) polyp. One colonic polyp revealed features of tubular adenoma, with moderate dysplasia. Another large pedunculated colonic polyp showed a tubulovillous adenoma with a focus of well-differentiated adenocarcinoma confined to the submucosa of the stalk. Adenomatous and carcinomatous epithelial changes can occur in Cronkhite-Canada syndrome.

Adenocarcinoma↗

PubMed2002

Computerized detection of colonic polyps at CT colonography on the basis of volumetric features: pilot study.

PURPOSE: To develop a computer-aided diagnosis (CAD) scheme for automated detection of colonic polyps on the basis of volumetric features and to assess its accuracy on the basis of colonoscopy, the standard. MATERIALS AND METHODS: Computed tomographic (CT) colonography was performed in patients with use of standard bowel cleansing, air insufflation, and helical scanning in supine and prone positions. The colon was extracted from volumetric data sets generated from transverse CT sections. Volumetric features characterizing polyps were computed at each point in the extracted colon. Polyps were detected by means of hysteresis thresholding and fuzzy clustering followed by a rule-based test on the basis of feature values. Locations of the detected polyps were compared with those detected at conventional colonoscopy. RESULTS: Forty-one cases were analyzed: nine cases with polyps and 32 without polyps. Each case with polyps had one polyp of clinically important size (six were 5-9 mm; three, 10 mm). Thus, there were 82 volumetric data sets, 18 included polyps. Eighty-nine percent (16 of 18) of the polyps were detected. Each of the two false-negative findings was detected in the other position; thus, 100% of polyp cases were detected, with 2.5 false-positive findings per patient. The false-positive findings were similar to those due to common perceptual errors. Most of the false-positive findings were easily distinguishable from true polyps by experienced radiologists. CONCLUSION: The CAD scheme has the potential to depict polyps with high sensitivity and an acceptable false-positive rate.

Adult↗

PubMed1992

Diminutive colonic polyps: an indication for colonoscopy.

A prospective study investigated the significance of solitary diminutive colonic polyps discovered during screening flexible sigmoidoscopy. Eighty-two patients with a solitary diminutive polyp (less than or equal to 5 mm) underwent colonoscopy after cold biopsy of the index polyp. Of the patients with adenomatous index polyps, 42.5 percent had proximal neoplastic polyps. Of the patients with hyperplastic index polyps, proximal neoplastic polyps were found in 38.9 percent. These data suggest that diminutive polyps identified during flexible sigmoidoscopy, whether adenomatous or hyperplastic, place the patient in the intermediate risk group for colorectal neoplasia. We recommend that any patient with polyps seen during screening sigmoidoscopy, regardless of histopathology, should undergo colonoscopy.

Biopsy↗