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Multiple colonic polyps as the initial presentation of malignant melanoma.

A 72-year-old-man was admitted to the Charleston Area Medical Center with a one-month history of mild anemia and positive stools for occult blood. A prior UGI series, small bowel series, and barium enema were normal. A colonoscopy revealed 12 sessile, non-pigmented colonic polyps, two of which were removed and sent for histologic examination. The final pathology report revealed malignant melanoma. Physical examination revealed no obvious evidence of skin lesions or melanoma elsewhere. Subsequent staging, which included a chest X-ray, a CT scan of the abdomen and brain, UGI endoscopy, and bone scan revealed a metastatic disease. The colonic lesions regressed in response to combination chemotherapy, and the patient's transfusion requirement decreased. However, the patient died of brain metastases 10 months after the initial diagnosis. This case emphasizes the fact that: 1. Metastatic lesions of the gastrointestinal tract may be the initial manifestation of malignant melanoma and may occur in the absence of a clinically obvious lesion; 2. Colonic metastases may simulate simple polyps endoscopically, particularly if they are non-pigmented; 3. Biopsy and histologic examination of any colonic polyp is essential in patients with a prior history of melanoma; and 4. Regression of gastrointestinal lesions from melanoma and subsequent clinical improvement may occur in response to chemotherapy.

Aged↗

Distribution of tissue bile acids in the human alimentary tract and colon polyps.

To determine the characteristic distribution of tissue-bound bile acids in the human alimentary tract and colon polyps, we measured the concentration of bile acids in the mucosal tissues of the alimentary tract obtained at autopsy and polyps obtained by endoscopic polypectomy, using enzymatic fluorimetry and gas-liquid chromatography. The concentration of tissue-bound bile acid, especially chenodeoxycholic acid, was significantly higher in the ileum or ascending colon than in the other portions of the alimentary tract. The bile acid level of polyps was also higher in the ascending colon than in the other portions of the colon. These results suggest that the high concentration of tissue-bound bile acids is obtained at the site of absorption of bile acids in the alimentary tract.

Aged↗

Peanut lectin stimulates proliferation in colonic explants from patients with inflammatory bowel disease and colon polyps.

BACKGROUND/AIMS: The TF antigen (galactose-beta 1,3-N-acetylgalactosamine alpha) is overexpressed in malignant and premalignant colonic epithelium. Previous studies have shown that peanut lectin (PNA), which binds TF, is mitogenic for normal human colonic epithelium. This study aimed to determine its effect on abnormal colonic epithelium. METHODS: Crypt cell proliferation rate (CCPR) was measured using vincristine arrest and mucus synthesis by incorporation of radiolabeled N-acetyl glucosamine in colonoscopic biopsy specimens cultured with and without PNA. RESULTS: Unstimulated CCPR was greater in patients with ulcerative colitis than in patients with histologically normal colon. PNA (25 micrograms/mL) produced a 25% average increase in CCPR in tissues from patients with ulcerative colitis, Crohn's disease, and colonic polyps. In ulcerative colitic biopsy specimens incubated with PNA, CCPR increased to more than double that of unstimulated normal colonic epithelium. In controls, the response to PNA was greater when adjacent specimens were positive for PNA (avidin-biotin) histochemistry than when they were negative. Mucus synthesis was increased by an average 75% over 24 hours by PNA. CONCLUSIONS: Increased TF expression by premalignant epithelia may allow stimulation of proliferation by dietary galactose N-acetylgalactosamine-binding lectins. If the hyperplasia-dysplasia cancer hypothesis is correct, this could explain the increased colon cancer risk in ulcerative colitis.

Acetylglucosamine↗

Ultrasonographic diagnosis of juvenile colonic polyps.

To reduce the risks of air-contrast barium enemas and colonoscopy, we studied the use of saline enemas for ultrasonographic examination of children with rectal bleeding. Thirty-nine children, from 2 years 8 months to 8 years 3 months of age, were examined. Juvenile colonic polyps were ultrasonographically demonstrated and histologically confirmed in 25 children; all the polyps were solitary and pedunculated, and were located in the splenic flexure in 3 children, the descending colon in 6, the sigmoid colon in 12, and the rectum in 4. Ultrasonographic findings by hydrocolonic ultrasonography were identical to those obtained by immersion ultrasonography of removed specimens. Hypoechoic areas within more hyperechoic polyps were shown histologically to be dilated glandular canals. The 14 children in whom no abnormal ultrasonographic findings were shown had no further rectal bleeding after resuming regular defecation, and 5 of these 14 had negative colonoscopic findings. No adverse reactions were noted in any child during or after the saline enema examination. We conclude that ultrasonographic examination with a saline enema is a safe and accurate method of assessing children with rectal bleeding, especially for the diagnosis of juvenile colonic polyps.

Child↗

[Electron microscopy of colonic polyps. II. Leuchtenberg's inclusion bodies].

Characteristic features of Leuchtenberger's inclusion bodies of adenomatous, adenopapillary and papillary polyps of the colon were studied by electron microscope. Authors believe that in the development of intracellular inclusion bodies focal degradation of the cytoplasma, of intercellular inclusion bodies, strangulation of certain areas of it may play a role. It is assumed that the development of inclusion bodies is a result of impairment of the cell membrane of proliferating, undifferentiated epithelial cells of the colonic mucosa. Increasing frequency of inclusion bodies in polyps undergoing malignant transformation seems to be an important morphologic feature.

Colonic Neoplasms↗

Value of a single forceps biopsy of colonic polyps.

The accuracy of colonoscopic biopsies in predicting the histological diagnosis of colonic polyps removed at colonoscopy or at laparotomy was studied. Forty-two patients were colonoscoped before the removal of 50 polyps. A single fractional biopsy was obtained from each lesion with the standard endoscopic biopsy forceps and was compared to the final histological diagnosis of each excised lesion. Thirteen (26%) of the singular fractional biopsies did not demonstrate the significant histological features of the excised polyps. These tiny biopsies do not adequately represent the entire polyp. Moreover, the 2- to 3-mm size of the biopsy does not permit the study of the central submucosal area of the polyp stalk, the critical area for assessing invasive malignancy. Histological examination of a completely excised polyp is essential for accurate diagnosis and appropriate therapy.

Biopsy↗

Barium enema examination: sensitivity in detecting colonic polyps and carcinomas.

We analyzed the sensitivity of the barium enema examination in 128 patients with 191 endoscopically proven colonic polyps and 12 carcinomas, relative to patient age, indications, and the type of examination used. Seventy-seven patients (60%) had rectal bleeding, and 51 (40%) patients with 87 lesions, including six carcinomas, did not. Overall roentgenographic sensitivity was 88%, with a 93% detection rate in patients less than 70 years old as compared to 76% for older patients. Sensitivity of single- and double-contrast barium enema examination was 82% and 91%, respectively. There were similar detection rates for lesions 1 cm or more in size (91% vs 95% for single- and double-contrast examinations, respectively), but double-contrast examination was slightly better at detecting smaller polyps (88%, vs 70% for single-contrast examination). Compared to colonoscopy, which has an average reported false-negative rate of 12% in detecting neoplasms, the barium enema is similarly reliable, less costly, and safer.

Adult↗

Magnifying endoscopy with indigo carmine contrast for differential diagnosis of neoplastic and nonneoplastic colonic polyps.

This study describes the feasibility of magnifying colonoscopy with indigo carmine dye contrast to distinguish neoplastic and nonneoplastic colonic polyps. This study sampled consecutive patients undergoing colonoscopy using an Olympus CF240ZI from January to October 2000 at Chang-Gung Memorial Hospital, Lin-Kou Medical Center. This study analyzed a total of 270 polyps. Indigo carmine (0.2%) was sprayed directly on the mucosa surface before observing the crypts using a magnifying colonoscope (1.5x-100x). The pit patterns were described using the classification proposed by Kudo. Finally, polypectomy or biopsy was performed for histological diagnosis. The study identified 155 adenomas, 99 hyperplastic polyps, 9 adenocarcinomas, and 7 other nonneoplastic lesions (harmatoma, inflammatory polyps, and mucosal tag). The pit pattern was analyzed for all lesions. Further classification into neoplastic (adenoma and adenocarcinoma) and nonneoplastic (hyperplastic and others) polyps revealed 156 neoplastic and 14 nonneoplastic polyps among the type III to type V pits and 92 nonneoplastic and 8 neoplastic polyps among the type I and II pits. The sensitivity of type III to type V pits in detecting neoplastic polyps was 95.1%, with a specificity of 86.8% and diagnostic accuracy of 91.9%. The positive likelihood ratio was 7.3, and the negative likelihood ratio was 0.06. Magnifying colonoscopy with indigo carmine dye contrast provides morphological detail that correlates well with polyp histology. Small flat lesions with typical type II pit pattern should have minimal neoplastic risk, thus endoscopic resection is not necessary.

Adenocarcinoma↗

The significance of diminutive colonic polyps found at flexible sigmoidoscopy.

In order to determine the importance of identification and follow-up of diminutive colonic polyps (DCPs) (i.e., those less than or equal to 5 mm in diameter), we studied 3006 patients undergoing flexible sigmoidoscopy. DCPs were found in 315 patients (10.5%). Biopsy of these lesions showed them to be nonneoplastic in 187 patients (59.4%) and neoplastic in 128 (40.6%). Overall, 35% of all DCPs found were neoplastic. Gross appearance of the lesions was found to be an unreliable means of predicting their histologic makeup. Of the 128 patients with neoplastic DCPs, 73 underwent further examination with barium enema and colonoscopy. Synchronous lesions were found in 57.5%. In 10 patients, synchronous lesions were of significance, including carcinomas, adenomas greater than or equal to 8 mm in diameter, or severely dysplastic adenomas. We conclude that all DCPs discovered at sigmoidoscopy should be biopsied and in patients in whom DCPs are found to be neoplastic, colonoscopy should be undertaken to search for proximal synchronous lesions.

Adenoma↗

Folate status and adenomatous colonic polyps. A colonoscopically controlled study.

PURPOSE: The aim of our study was to assess any association of folate with development of colonic adenomas. METHODS: Serum and red blood cell folate levels were measured in 62 colonoscopically and histologically evaluated patients with colon adenomas (Group A) and in 50 selected colonoscopically negative controls (Group B). Patients with colon polyps underwent colonoscopy for alterations of bowel habits or abdominal pain, and detected polyps were found coincidentally. Controls underwent colonoscopy for alterations of bowel habits or abdominal pain. There was no difference in hematocrit between the two groups. RESULTS: The mean serum folate level in patients with colonic adenomas was 4.57 ng/ml +/- 2.8 standard deviations (SD), and the mean red blood cells folate levels were 536 ng/ml +/- 273.3 (SD). In controls the mean folate levels in serum and red blood cells were 5.09 ng/ml +/- 2.7 (SD) and 743.8 ng/ml +/- 297.1 (SD), respectively. The red blood cell folate level of colon adenoma patients was statistically lower than the respective level of controls at a highly significant level (P < 0.01). CONCLUSIONS: We suggest that depressed red blood cell folate levels are associated with development of colonic adenomas.

Adenoma↗

High prevalence of colonic polyps in patients with acromegaly. Influence of sex and age.

BACKGROUND: An association between acromegaly and colonic polyps has been reported, although risk factors are still uncertain. METHODS: Full colonoscopy was performed with a fiberoptic colonoscopy on 31 acromegalic patients, 11 men and 20 women aged 27 to 85 years (mean, 52.2 years), and on 236 subjects, 127 men and 109 women aged 23 to 84 years (mean, 50.1 years), referred for hemorrhoids, who were considered controls. The colonoscopic findings were evaluated in relation to demographic, clinical, and hormonal data pertaining to the two groups. RESULTS: The prevalence of either adenomatous or hyperplastic polyps was higher in acromegalic patients than in controls (38% vs 14% and 26% vs 10%, respectively; P < .001, respectively). Acromegalics with and without colonic adenomas did not differ significantly in growth hormone and insulinlike growth factor I levels or duration of acromegalic disease and its status (activity or remission); however, patients with adenoma were younger (median age, 50.5 vs 59 years; range, 27 to 85 years vs 39 to 66 years; P < .05). An opposite age pattern was observed in the control group. Indeed, the prevalence of adenoma in acromegalic patients was much higher than that in controls among those less than 50 years of age (46% vs 7%, P < .001); the difference was less remarkable at older ages. Adenomatous polyps were more frequently found in male subjects, in both patients and controls (45% vs 33% [not significant] and 19% vs 9% [P < .05], respectively). CONCLUSIONS: Acromegaly may carry an increased risk of colonic adenoma, especially in younger patients, who usually display more aggressive disease. A smaller increase in risk was observed in elderly patients, in whom disease is reportedly milder. We suggest that acromegalic patients should undergo screening colonoscopy.

Acromegaly↗

Inherited syndromes of colon polyps.

Recognition of the mendelian dominant inherited syndrome of familial polyposis coli in the 1930s has been followed by the recognition of many inherited colonic polyposis syndromes. The recognition of different histological types of colon polyps was associated by the gradual recognition that some, such as the hamartomatous polyps, do not progress into adenocarcinoma, and others, such as various adenomas have a greater or lesser propensity to eventually give rise to invasive cancer. As the host of inherited syndromes expanded and were more widely recognized, additional inherited characteristics became apparent: such tumors as breast and thyroid associated with Cowden's syndrome, ovarian cysts and sex cord tumors with Peutz-Jeghers syndrome, and, of course, the soft tissue, bony tumors, ampullary cancers, and fibroadenomas associated with Gardner's syndrome. In recent years, genetic markers for the various syndromes have been studied, and in some cases confirmed. This whole field is rapidly developing and is briefly covered. All the steps and influencing factors in cancer development are shown in one phase or another of the polyp-cancer sequence in these inherited syndromes.

Colonic Polyps↗

Computer-aided detection of colonic polyps using low-dose CT acquisitions.

RATIONALE AND OBJECTIVES: This report proposes an alternative method for the automatic detection of colonic polyps that is robust enough to be directly applicable on low-dose computed tomographic data. MATERIALS AND METHODS: The polyp modeling process takes into account both the gray-level appearance of polyps (intensity profiles) and their geometry (extended Gaussian images). Spherical harmonic decompositions are used for comparison purposes, allowing fast estimation of the similarity between a candidate and a set of previously computed models. Starting from the original raw data (acquired at 55 mA), five patient data sets (prone and supine scans) are reconstructed at different dose levels (to 5 mA) by using different kernel filters, slice overlaps, and increments. Additionally, the efficacy of applying an edge-preserving smoothing filter before detection is assessed. RESULTS: Although image quality decreases when decreasing acquisition milliamperes, all polyps greater than 6 mm are detected successfully, even at 15 mA. Although not important at high doses, smoothing improves detection results for ultra-low-dose (tube current<15 mA) data. CONCLUSION: The advantage of low-dose scans is a significant decrease in effective dose from 4.93 to 1.61 mSv while retaining high detection values, particularly important when thinking of population screening.

Algorithms↗

Early invasive carcinoma in colonic polyps. A review of the literature with emphasis on the assessment of the risk of metastasis.

The proper treatment of adenomatous colonic polyps containing small foci of invasive cancer is controversial because the metastatic potential of these lesions is not precisely known. This article critically reviews all known English language studies of this lesion. Before the introduction of colonoscopic polypectomy, the estimated incidence of metastasis from this lesion was 10.4% (based on 12 studies containing 347 polyps), with a confidence interval (95% level) of 7.4 to 14.1. The incidence of metastasis estimated from lesions removed via colonoscopic polypectomy was 10.1% (based on 13 studies containing 188 polyps), with a confidence interval of 5.9 to 14.8. Differences in the definitions of the involved lesions, study designs, and indications for resection cause problems with case selection bias and make comparison of studies difficult. These problems are discussed in detail. Most studies had broad confidence intervals for the estimated incidence of metastasis because of small sample size. The histopathologic criteria, as reflected in the literature, for considering polypectomy alone as adequate treatment for this lesion are summarized and discussed.

Carcinoma↗

Cholesterol emboli in a colonic polyp.

Cholesterol emboli usually occur after vascular surgery or angiographic procedures in patients with extensive arteriosclerosis. Atheroemboli also occur spontaneously in patients receiving anticoagulant drugs. Ischemic colitis, gastric hemorrhage, and acute pancreatitis are the more common gastrointestinal manifestations of cholesterol emboli. Here I report, for apparently the first time, cholesterol emboli in a colonic polyp.

Colonic Polyps↗

[Laparoscopy-assisted colonic polypectomy or how to be helped by laparoscopy to prevent colectomy in benign colonic polyps considered to be unresectable by colonoscopy].

The aim of this study was to prospectively evaluate the role of laparoscopic surgery in all patients presenting with colonic polyps. From April 1994 to April 1996, 16 consecutive patients were treated. The laparoscopy starts the procedure, then a colonoscopy easily and rapidly locates the colonic lesion. Under laparoscopic supervision a new snare polypectomy is often possible. If polypectomy remains impossible, a mini-laparotomy is performed above the polyp and allows polypectomy by extra-peritoneal colotomy. In one case, the polyp was not found on colonoscopy. Colonoscopic polypectomy was possible in 6 cases (40%), and 9 mini-laparotomies were necessary (60%). No colectomy was performed. The final histologic result showed two Dukes A carcinomas justifying secondary wide colectomy. Laparoscopy-assisted polypectomy is a safe and efficient procedure, allows complete excision of polyps and may avoid a colonic resection.

Aged↗