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PubMed1996

Instant technetium 99m hexamethyl propylenamine oxime-labeled leukocyte scan compared with colonoscopy in early assessment of disease extent and activity in acute colitis.

AIM: This study was undertaken to evaluate technetium 99m (Tc 99m) hexamethyl propylenamine oxime (HMPAO)-labeled leukocyte scintigraphy for assessment of disease extent and activity in acute colitis. PATIENTS AND METHODS: Twenty-seven patients, hospitalized because of acute watery and/or bloody diarrhea, were investigated using both total colonoscopy and Tc 99m HMPAO-labeled leukocyte scintigraphy within 48 hours after admittance. RESULTS: Final diagnoses were ulcerative colitis in 14 patients, Crohn's disease in 7 patients, and infectious colitis in 6 patients. Using colonoscopy as the reference method, the maximum extent of colitis was correctly assessed by the leukocyte scan in 18 patients (67 percent), although rectal engagement was not visualized in 5 (19 percent). In six additional patients, there was almost complete agreement between the two methods. One other patient, with leftsided ulcerative colitis, was erroneously assessed as having total extent. Two other patients (one with Crohn's colitis and one with infectious colitis) had different segments incorrectly assessed. Sensitivity, specificity, and diagnostic accuracy of scintigraphy in detecting active inflammatory segments were 0.85, 0.83, and 0.85, respectively. Intensity of inflammatory activity assessed by the leukocyte scan correlated significantly with colonoscopic assessment (r = 0.719; P < 0.0001). CONCLUSION: Information regarding extent, localization, and disease activity in patients with acute colitis of inflammatory or infectious origin may be satisfactorily obtained using Tc 99m HMPAO-labeled leukocyte scanning. The noninvasive nature of the method makes it an attractive early alternative to other investigational procedures such as total colonoscopy or barium examination, particularly in cases with an established diagnosis of inflammatory bowel disease.

Acute Disease↗
PubMed1994

Colonoscopy of acute colitis. A safe and reliable tool for assessment of severity.

Complications that might lead to surgery in severe attacks of ulcerative colitis have been found to be correlated with the depth of colonic ulcerations as measured by pathological examination of colectomy specimens. In order to evaluate the value of colonoscopy for the assessment of colonic ulcerations, we have reviewed the clinical, biological, colonoscopic, and anatomical findings in 85 consecutive patients with attacks of ulcerative colitis involving at least the rectosigmoid and part of the descending colon, seen in our center between 1981 and 1989. All had colonoscopy performed by a senior endoscopist at entry. Extensive deep colonic ulcerations were diagnosed in 46 of them, and moderate endoscopic colitis in 39. No complication related to colonoscopy occurred except for one colonic dilatation. Forty-three of the 46 patients with severe endoscopic colitis were operated upon; 38 of them failed to improve with high-dose corticosteroids and five had a toxic megacolon. Extensive ulcerations reaching at least the circular muscle layer were found at pathological examination of colectomy specimen in 42 of the 43 patients. Conversely, 30 of 39 patients with moderate endoscopic colitis went into clinical remission with medical treatment, and only nine patients needed further surgery because of medical treatment failure. Six of these nine patients underwent another colonoscopy prior to colectomy, and all six showed features of severe endoscopic colitis. Deep ulcerations reaching the circular muscle layer were found at pathological examination in five of these six patients and in one additional patient whose colonoscopy had been performed 21 days before colectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

Distension-stimulated propagated contractions in human colon.

To investigate the mechanisms for elicitation of peristaltic activity in the human colon, we studied the effect of balloon distension of the transverse, descending, and sigmoid colon and the rectum. Fifteen healthy subjects were studied by means of a colonoscopically positioned probe carrying a 5-cm latex balloon. After positioning of the probe, stepwise distension was performed for each colonic segment (transverse, descending, sigmoid, rectum), and the onset of large (> 50 mm Hg) and small (< 50 mm Hg) propagated waves was observed. Analysis of the tracings showed: (1) In 8/15 subjects (53.3%), balloon distension elicited propagated contractions, but these contractions were qualitatively different from the spontaneously occurring high-amplitude propagated contractions previously found to occur in association with defecation. Therefore, intraluminal distension is probably not the cause of defecation-associated high-amplitude propagated contractions. (2) Pain reports were poorly correlated with propagated contractions elicited by balloon distension, suggesting that these contractions are not the cause of the pain produced by balloon distension. (3) The transverse colon shows lower pressures, fewer pain reports, and fewer large propagated contractions in response to balloon distension as compared to the descending and the sigmoid colon.

Adult↗
PubMed1994

Safety and clinical efficacy of flexible sigmoidoscopy and colonoscopy for gastrointestinal bleeding after myocardial infarction. A six-year study of 18 consecutive lower endoscopies at two university teaching hospitals.

The risks versus benefits of flexible sigmoidoscopy and colonoscopy performed within three weeks of myocardial infarction were studied in nine consecutive patients who underwent sigmoidoscopy and in nine consecutive patients who underwent colonoscopy at two university hospitals. Indications for sigmoidoscopy were red blood per rectum in seven and occult blood in the stools in two. Sigmoidoscopy provided the diagnosis in three, including colon cancer in two and bleeding internal hemorrhoids in one, and provided helpful information in three. Sigmoidoscopy led to colon cancer surgery in two patients, and polypectomy of a 1-cm adenoma in one. Of two highly unstable patients before sigmoidoscopy, one developed second-degree heart block and frequent premature ventricular contractions 3 hr after sigmoidoscopy. No sigmoidoscopic complications occurred in the seven relatively clinically stable patients. Indications for colonoscopy included red blood per rectum in five, occult blood in the stools in three, and melena in one. Colonoscopy provided the diagnosis in five, including one each with colon cancer, internal hemorrhoids, large adenoma, ischemic colitis, and angiodysplasia. Colonoscopy resulted in colon cancer surgery in one patient and endoscopic polypectomies in three patients. Of two moderately unstable patients before colonoscopy, one developed asymptomatic bradycardia during colonoscopy. No colonoscopic complications occurred in the seven clinically stable patients. This study suggests that recent myocardial infarction is not an absolute contraindication to sigmoidoscopy or colonoscopy, that sigmoidoscopy is beneficial in medically stable patients with significant gastrointestinal bleeding, and that colonoscopy may be beneficial in selected, highly stable patients with significant gastrointestinal bleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2001

Twenty-four hour recordings of colonic motility in patients with diverticular disease: evidence for abnormal motility and propulsive activity.

INTRODUCTION: Diverticular disease of the colon is one of the most common pathologic entities in western countries. Although altered motility of the large bowel is commonly believed to be one of the major pathophysiologic mechanisms, no convincing evidence has been reported yet. In fact, only a few conflicting studies concerning distal colonic motility (with no information on forceful propulsive activity) are available in the literature. PURPOSE: The purpose of the present study was to investigate basal and stimulated (postprandial) colonic motility from the transverse (not affected), descending, and sigmoid colon in patients with diverticular disease, together with detection of high-amplitude propagated contractions (mass movements). Motility data from patients were compared with those obtained in healthy control subjects. METHODS: Ten patients and 16 control subjects of both sexes were recruited for the study. In all subjects, colonic motility was recorded for a 24-hour period by a colonoscopically positioned manometric catheter. Two 1000-kcal mixed meals were served during the study. RESULTS: Compared with control subjects, patients with diverticular disease displayed significantly increased amounts of motility in the affected segments; the response to a physiologic stimulus (meal) was also abnormal in the patients' group. Diverticular disease patients also had a significant increase of forceful propulsive activity compared with control subjects (average = 10.3 +/- 2.7/subject/day high-amplitude propagated contractions for patients and 5.5 +/- 0.8/subject/day for control subjects; P = 0.051); interestingly, about 20 percent of such activity was abnormal, being propagated in a retrograde fashion. CONCLUSIONS: We concluded that patients with diverticular disease of the colon have abnormal motor and propulsive activities of the large bowel, which are confined to the affected segments.

Adult↗
PubMed2001

Flow cytometric and histologic evaluation in a large cohort of patients with ulcerative colitis: correlation with clinical characteristics and impact on surveillance.

PURPOSE: To examine the prevalence of DNA aneuploidy as a function of the extent of ulcerative colitis and to study the correlation of aneuploidy with clinical characteristics. Furthermore, the occurrence of aneuploidy and dysplasia during colonoscopic surveillance was studied in a subset of these patients. METHODS: By analyzing 5404 biopsy samples of 368 patients with ulcerative colitis, we have evaluated the importance of DNA ploidy measured by flow cytometry. We have also investigated the influence of extent (219 patients with extensive or total colitis vs. 149 patients with localized colitis) and duration of colitis on the development of dysplasia (patients with biopsy specimens that showed inflammation alone were compared with those with biopsy specimens that were equivocal or positive for dysplasia) and aneuploidy. Included was a subgroup of patients with ulcerative colitis and primary sclerosing cholangitis (n = 16). RESULTS: Aneuploidy was found in 8.7 percent (32/368) of all patients. The prevalence of aneuploidy increased by the extent of ulcerative colitis (2 percent localized, 6.8 percent extensive colitis, 14.9 percent total colitis). The frequency of aneuploidy was higher in patients with disease duration longer than 10 years (P = 0.007). Patients with ulcerative colitis and primary sclerosing cholangitis were more likely to develop aneuploidy (9/16, 56.3 percent vs. 14/120, 11.7 percent; P < 0.001) and dysplasia (4/16, 25 percent vs. 10/120, 8.3 percent; P = 0.06) than patients without primary sclerosing cholangitis. CONCLUSION: Because DNA aneuploidy represents an early alteration during neoplastic transformation in ulcerative colitis, flow cytometry is a valuable tool in the surveillance of those patients. Primary sclerosing cholangitis represents an additional risk factor for the development of DNA aneuploidy and dysplasia.

Aneuploidy↗
PubMed2001

Source of errors in the evaluation of early rectal cancer by endoluminal ultrasonography.

PURPOSE: Although preoperative evaluation of early rectal cancers can be done by endoluminal sonography and by means of colonoscopic findings, it is still controversial whether endoluminal sonography can effectively discriminate mucosal from submucosal lesions. This study was performed to verify objective causes of errors in the evaluation of early rectal cancer (T0/1) using a review of videotaped endoluminal sonography images. METHODS: Eighty-nine patients with suspected early rectal cancer on endoluminal sonography were included. Two different scanners with appropriate probes were used according to tumor location, i.e., transrectal ultrasonography was used to scan up to 8 cm of the rectum above the anal verge, whereas endoscopic ultrasonography was used to assess higher lesions. Endoluminal sonography images were correlated with histologic infiltration and were reevaluated carefully to identify sources of errors. RESULTS: Sensitivity and specificity were 83.1 and 96.5 percent, respectively, for tumor staging, whereas sensitivity was very low compared with specificity (16.7 vs. 90.2 percent) for metastatic lymph nodes. Endoluminal sonography images showed irregularity of the underlying tumor border (P < 0.01) and hypoechoic blurring or cutoff of the inner and outer hypoechoic layers (P < 0.001), all of which closely correlated with histologic infiltration of tumor cells. Overstaging occurred more than twice as often as understaging in tumor reevaluation (14 vs. 5 occurrences). In contrast to tumors, lymph nodes showed a similar amount of both overstaging (four cases) and understaging (five cases). The sources of errors were summarized as five types: false instrumentation, interpretive errors, anatomic defects, imaging failure, and inevitable errors. CONCLUSIONS: Because false instrumentation, interpretive errors, and anatomic defects were considered preventable, 23 (82.1 percent) of the 28 errors might have been avoided. Therefore, a clear image by endoluminal sonography can effectively distinguish mucosal from submucosal lesions in early rectal cancer.

Diagnosis, Differential↗
PubMed2001

Diet and colorectal adenoma in Japanese males and females.

PURPOSE: The purpose of this study was to assess the relationship between risk of colorectal adenoma and dietary intake of nutrients and foods. METHODS: In 1992, diet was assessed by a semiquantitative food-frequency questionnaire in a cohort of the Takayama Study in Japan. Patients were 181 male and 98 female cohort members who were newly histologically proved to have colorectal adenoma at colonoscopic examination between January 1, 1993, and December 31, 1995. Controls were 12,607 males and 15,754 females who had no history of colorectal polyp, adenoma, and cancer at baseline (1992) and were not diagnosed to have these diseases during the follow-up period. RESULTS: In males, the risk of adenoma was significantly associated with intake of animal protein and vitamin A (relative risk, 1.42; 95 percent confidence interval, 1.00-2.04; and relative risk, 1.51; 95 percent confidence interval, 1.04-2.20, for the highest vs. lowest tertiles, respectively; P for trend = 0.048 and 0.03, respectively) after controlling for age, years of smoking, and alcohol intake. A significantly inverse association was observed for carbohydrate intake after controlling for the covariates (relative risk, 0.52; 95 percent confidence interval, 0.32-0.82, for the highest vs. lowest tertiles; P for trend = 0.02). Intakes of animal fat and cholesterol were marginally associated with risk of adenoma. CONCLUSION: Some dietary components such as animal protein and carbohydrate, which have been associated with risk of colorectal adenoma or cancer in western populations, were also associated with risk of colorectal adenoma in the Japanese population.

Adenoma↗
PubMed2001

Inadequacy of colonoscopy revealed by three-dimensional electromagnetic imaging.

INTRODUCTION: It is generally accepted that clinicians performing colonoscopy should reach the cecum in at least 90 percent of examinations. However, little attention has been paid to whether the endoscopist correctly estimates the amount of colon actually seen. METHODS: During colonoscopy, endoscopists were asked to state how far they had reached. This was compared with the amount of colon actually seen, as assessed by a novel electromagnetic imaging device that recorded a three-dimensional position of the scope within a magnetic field pervading the patient's abdomen. If electromagnetic imaging showed that the cecum had not been reached, the endoscopist was asked to use the electromagnetic imaging system to determine whether it helped advance the colonoscope further. RESULTS: In 119 patients undergoing colonoscopy, clinical assessment of position reached was correct in only 92 (77.3 percent). When the endoscopists stated that cecal landmarks had been seen (n = 85), the scope was distal to the cecum in seven cases (8.2 percent). When cecal landmarks had not been seen (n = 34), the endoscopist's assessment of the position of the scope was accurate in only 14 (41.2 percent). The use of electromagnetic imaging in this latter group assisted passage to the cecum in 26 cases (76.5 percent). CONCLUSION: Despite assumed visualization of the cecum, inadequate colonoscopy highlights the potential for missing significant pathology in the right colon.

Adult↗
PubMed1999

Neoplasia after ureterosigmoidostomy.

PURPOSE: The occurrence of neoplasia after ureterosigmoidostomy is well-documented in the literature. Because of its rarity, few general surgeons will gain significant exposure to this entity, and colorectal surgeons are likely to be involved with the care of these patients. The purpose of this article is to apprise colorectal surgeons about the management of neoplasia after ureterosigmoidostomy and to familiarize them with the unique anatomy of the reconstructed pelvis. METHODS: We performed a MEDLINE search to identify articles on ureterosigmoid tumors. The theories regarding the cause and pathology of these tumors were critically analyzed. A consensus was developed for screening patients with ureterosigmoidostomy and for treatment of neoplasia. RESULTS: The incidence of carcinoma after ureterosigmoidostomy ranges from 2 to 15 percent. Polyps are more common, and it seems that these tumors also follow the sequence of adenocarcinoma that is seen in the common variety of colorectal neoplasia. Neoplastic changes begin with the interaction of urine and feces and the healing colonic mucosa. Both production of nitrosamines by the action of bacteria on urine and DNA damage caused by reactive oxygen radicals produced by neutrophils at the healing anastomosis have been implicated in the pathogenesis of neoplasia. The latent period between formation of ureterosigmoidostomy and the appearance of carcinoma is between 20 and 26 years. Obstructive urinary symptoms that develop more than two years after ureterosigmoidostomy should be viewed with suspicion. The patient should be investigated with a CT scan and colonoscopy, and a barium enema may be required to delineate the anatomy further. If a benign tumor is encountered during colonoscopy, it may be removed by snare polypectomy. For a malignant tumor the segment of colon with ureteric implants should be excised, along with its lymphatic drainage. Bowel continuity is restored primarily, and the ureters are implanted in an ileal conduit. CONCLUSIONS: Patients with ureterosigmoidostomy should be followed closely for the rest of their lives. The aim of screening is to identify and treat neoplasia before malignancy develops. Furthermore, early detection of neoplasia by close screening will improve survival. Although urine cytology and occult blood are inexpensive tests, colonoscopy remains the criterion standard for follow-up of these patients. Annual colonoscopic surveillance should be started soon after the ureterosigmoidostomy but not later than five to six years after the procedure. Patients who are noncompliant with the vigorous follow-up schedule should be offered the option of resection of the colonic segment at risk with urinary diversion.

Adenocarcinoma↗
PubMed1999

Cigarette smoking, alcohol use, and colorectal adenoma in Japanese men and women.

PURPOSE: The aim of this study was to examine the relationships between smoking and alcohol use and risk of colorectal adenoma. METHODS: Information about smoking, alcohol use, and other lifestyle variables were obtained prospectively from 14,427 male and 17,125 female residents in a city of Gifu Prefecture, Japan, by a self-administered questionnaire in September, 1992. Colorectal adenomas were newly diagnosed in 181 men and 78 women in this cohort between January, 1993 and December, 1995 by colonoscopic examination at two major hospitals of the city. Gender-specific and site-specific relative risks and 95 percent confidence intervals adjusted for age and for age plus other potential confounding factors were calculated by using logistic regression models. RESULTS: Thirty or more years of smoking was significantly associated with risk of adenoma in general compared with never having smoked in both men and women (relative risk, 1.60; 95 percent confidence interval, 1.02-2.62 and relative risk, 4.54; 95 percent confidence interval, 2.04-9.08, respectively). Effect of smoking was stronger in the proximal colon. After adjusting for age and carbohydrate intake, total alcohol intake was not associated with risk of adenoma in any site in the colon in men. Sake drinkers were at significantly increased risk of adenoma in general, but the dose-response relationship was not statistically significant. Risk of adenoma in the rectum was not significantly increased for those who consumed >30.3 g/day of ethanol (relative risk, 5.7). CONCLUSION: These data suggest that smoking is a risk factor of adenoma in Japanese men and women. The role of alcohol, however, is less clear.

Adenoma↗
PubMed1999

Colorectal cancer after surveillance colonoscopy: false-negative examination or fast growth?

PURPOSE: Colonoscopy is the preferred method for colorectal cancer surveillance of high-risk patients. Despite its high sensitivity, polyps or cancers may be undetected by colonoscopy and later attributed to an accelerated adenoma-carcinoma sequence. This study assesses how the characteristics of colorectal cancers found at intervals between surveillance relate to the adenoma-carcinoma sequence and its prevention. METHODS: The records of 557 patients with colorectal cancer that were diagnosed from January 1, 1990, to December 31, 1996, were reviewed to identify those patients who had prior colonoscopic surveillance within 60 months of their diagnosis. RESULTS: There were 29 (5.2 percent) patients who had one or more colonoscopies before diagnosis of their colorectal cancer. Mean interval between diagnosis and prior colonoscopy was 23 (range, 4-59) months. The distribution of cancers included nine cecum, two ascending, three hepatic flexure, five transverse, one splenic flexure, three descending, two sigmoid, three rectum, and one anal canal. The mean tumor size was 4.4 cm for the cecum and 2.4 cm for all other locations. There were 7 Tis, 6 T1, 4 T2, and 12 T3 lesions. Six patients with T3 lesions had prior colonoscopies within 24 months of the diagnosis. Three of four patients with lymphatic metastases had tumors in the cecum. Twenty tumors (69 percent) were well or moderately differentiated. Mean follow-up was 41 (range, 7-95) months with two local recurrences and two unrelated deaths. CONCLUSIONS: Size, differentiation, and stage of colorectal cancer in addition to the interval to diagnosis suggest that the majority of cancers found during surveillance colonoscopy followed prior false-negative examinations. Because cecal landmarks are most constant, prior photographic documentation may help to prove or disprove fast growth of cancers found in the cecum during surveillance colonoscopy.

Aged↗
PubMed1999

Vitamin and calcium supplement use is associated with decreased adenoma recurrence in patients with a previous history of neoplasia.

INTRODUCTION: Although some have suggested that certain vitamins or calcium supplements may reduce adenoma recurrence, our own prior retrospective study found no such effects. The purpose of this case-control study was to further investigate whether regular vitamin or calcium supplement intake influenced the incidence of recurrent adenomatous polyps in patients with previous neoplasia who were undergoing follow-up colonoscopy. METHODS: This study enrolled 1,162 patients who underwent colonoscopy by one of three surgeons at Columbia-Presbyterian Medical Center in New York City between March 1993 and February 1997. Of these patients 448 (250 males) had a previous diagnosis of colorectal neoplasia (cancer, adenomas, or dysplasia). Of these, 183 (40.8 percent) had an adenoma at the index colonoscopy. Information was collected on personal and family history of colonic diseases, cigarette smoking, medication, and vitamin and micronutrient supplement usage on a questionnaire that was completed by the patients before the colonoscopy. Odds ratios were obtained by unconditional logistic regression analysis, adjusting for age and gender, and used adenoma recurrence at index colonoscopy as the outcome. RESULTS: The mean interval between colonoscopic examinations was 37 months for the recurrent adenoma group and 38 months for the nonrecurrent group of patients (P = not significant). In this case-control study we found a protective effect for the use of vitamin supplements in general (any vitamin) on the recurrence of adenomas (odds ratio, 0.41; 95 percent confidence interval, 0.27-0.61). Specifically, this protective effect was observed for the use of multivitamins (odds ratio, 0.47; 95 percent confidence interval, 0.31-0.72), vitamin E (odds ratio, 0.62; 95 percent confidence interval, 0.39-0.98), and for calcium supplementation (odds ratio, 0.51; 95 percent confidence interval, 0.27-0.96). Nonsignificant protective effects were noted for carotene/vitamin A, vitamin D, and vitamin C. CONCLUSIONS: The use of multivitamins, vitamin E, and calcium supplements were found to be associated with a lower incidence of recurrent adenomas in a population of patients with history of previous colonic neoplasia. Prospective, randomized trials are needed to better assess the impact of these agents and to determine whether the use of these supplements is associated with a protective effect against recurrent adenomas.

Adenomatous Polyps↗
PubMed2000

Invasive colon cancer derived from a small superficial depressed cancer: report of a case.

A 64-year-old male in May 1997 was diagnosed by colonoscopy and a barium enema examination as having an invasive cancer in the transverse colon. Pathologic study of the resected surgical specimen revealed a well-differentiated adenocarcinoma invading the muscularis propria. He had a colonoscopic examination in 1991 and was diagnosed as having multiple adenomas, which were endoscopically removed. After that he had annual colonoscopy or barium enema examination follow-ups. At endoscopy in February 1994, a superficial depressed cancer 6 mm in diameter had been detected. However, the cancer was not seen again in several endoscopic examinations until one in 1997. Because the location of the lesion detected in 1994 and that of the invasive carcinoma detected in 1997 were identical, it was considered that the superficial depressed cancer developed, 40 months later, to an advanced cancer. Doubling time was calculated as 8.4 months.

Adenocarcinoma↗
PubMed2000

The natural history of isolated rectosigmoid adenomatous polyps: is flexible sigmoidoscopy a safe alternative for surveillance?

PURPOSE: Colonoscopic surveillance is recommended for patients with adenomatous polyps. Significant cost savings would result from identification of subgroups of patients in whom less costly surveillance would suffice. This study was performed to determine the natural history of patients undergoing removal of isolated rectosigmoid adenomas and to establish whether flexible sigmoidoscopy might be adequate for follow-up. METHODS: A retrospective review of a database of 7,677 colonoscopies, from 1990 to 1996, identified patients who had a minimal follow-up of two years after removal of adenomatous polyps isolated to the rectosigmoid. Polyps detected on surveillance colonoscopy were categorized as distal (< or =60 cm from anal verge), proximal (>60 cm from anal verge), and diffuse (proximal plus distal). The risk of polyp formation was determined by actuarial analysis using the Kaplan-Meier method. RESULTS: Sixty-two patients undergoing surveillance for adenomas met inclusion criteria. At the index colonoscopy, 124 isolated rectosigmoid polyps were identified. The median polyp size was 1 cm and median frequency was one polyp. The median follow-up time for the entire cohort (N = 62) was 53 months. At follow-up surveillance colonoscopy, 105 additional adenomas were discovered and removed in 40 patients. No malignant polyps were detected. The pattern of polyps detected were proximal (n = 19), rectosigmoid (n = 16), and diffuse (n = 5). CONCLUSIONS: The majority (65 percent) of patients with isolated rectosigmoid polyps have additional polyps on long-term surveillance, and 60 percent of patients will have these polyps located proximal to the reach of a sigmoidoscope. Therefore, flexible sigmoidoscopy is not a safe alternative for surveillance of patients with isolated rectosigmoid polyps.

Adult↗
PubMed2000

Hyperplastic polyps: "more than meets the eye"? Report of sixteen cases.

The vast majority of hyperplastic polyps are small, left-sided, and inconsequential in nature. However, hyperplastic polyps that are large, right-sided, mixed, and found in association with a family history of carcinoma may represent an "atypical" group, and their clinical significance is uncertain. We believe that these atypical lesions should not be lumped together with the common variety of diminutive hyperplastic polyps. Rather, when such hyperplastic polyps are encountered, they should be excised and the patient should be placed on regular colonoscopic surveillance.

Cell Transformation, Neoplastic↗
PubMed2000

Flat adenoma of the large bowel: re-evaluation with special reference to central depression.

PURPOSE: The aim of this study was to re-evaluate the clinicopathologic features of flat adenomas with special reference to the role of central depression found in flat adenomas. METHODS: Clinicopathologic features, such as grade of atypia by size, site, central depression, coexisting lesions, gender, and family history of cancer, were evaluated in 236 flat adenomas from 183 patients selected retrospectively and prospectively. RESULTS: Of the 236 flat adenomas, 175 had mild, 33 had moderate, and 28 had severe (i.e., intramucosal carcinoma) atypia. The frequency of severe atypia correlated positively with size. Severe atypia were significantly more frequent in females (21 percent in females and 10 percent in males; P < 0.05). Sixteen percent of flat adenomas in patients with coexisting cancer showed severe atypia, which was significantly more than those without coexisting cancer (P < 0.05). The frequency of multiple flat adenomas in patients with two or more family members with cancer was 53 percent, which was significantly higher than in patients with one or no family members with cancer (P < 0.05). Central depression was observed in 19 percent of flat adenomas. The rate of severe atypia (22 percent) of flat adenomas with central depression was significantly higher than that (9 percent) of flat adenoma without central depression (P < 0.05). Patients who had flat adenomas with central depression had a higher incidence of coexisting cancer and cancer in the family (P < 0.05 and P < 0.01). CONCLUSION: At colonoscopic examination consideration should be given for the increased potential to become malignant in flat adenomas, especially those with central depression and in patients with a history of malignancy or with a family history of malignancy.

Adenoma↗