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PubMed1992

Ultraviolet laser-induced fluorescence of colonic polyps.

Ultraviolet laser-induced fluorescence was examined in vivo to determine whether the technique can reliably distinguish between hyperplastic and adenomatous polyps of the colon. Spectra from 86 normal colonic sites, 35 hyperplastic polyps, and 49 adenomatous polyps were recorded in vivo. Polyp type was independently determined by two senior pathologists who were unaware of the fluorescence measurement. A multivariate linear regression analysis was used to differentiate spectra from hyperplastic and adenomatous polyps and resulted in a sensitivity, specificity, predictive value positive, and predictive value negative for identifying adenomatous polyps of 86%, 80%, 86%, and 80%, respectively. These values were not significantly different from the accuracy of routine clinical pathology. Thus, ultraviolet laser-induced fluorescence appears to show promise as a means for distinguishing tissue types. However, further experience is needed before its routine clinical use can be recommended. Significant changes in the fluorescence spectra occurred postmortem, suggesting that future studies of laser-induced fluorescence of colonic tissue must use data acquired in vivo.

Aged↗
PubMed2003

[Laparoscopic surgery for endoscopically irretrievable colonic polyps].

AIM: The vast majority of benign colorectal neoplasms can be safely removed by colonoscopic polypectomy; while peduncolated polyps can be easily endoscopically excised, the removal of sessile polyps may be more difficult. METHODS: Between January 1997 and December 1998, 12 patients underwent laparoscopic or laparoscopic-assisted colonic resection for treatment of endoscopically irretrievable colonic polyps; this group was compared to 12 patients who underwent a laparotomic approach for polyps in the same period of time and to 23 patients who previously underwent similar laparoscopic resections. RESULTS: There were no significant differences between laparoscopic and laparotomic groups. CONCLUSION: Laparoscopic or laparoscopic-assisted colonic resection for treatment of endoscopically irretrievable colonic polyps remains our preferred method of treating these lesions.

Aged↗
PubMed1994

Clinical evaluation for colonic polyps: usefulness of signs and symptoms in diagnosis.

This article reports a prospective cross-sectional study of the relationship between various signs and symptoms commonly ascribed to colorectal cancer and the presence or absence of colonic polyps found by colonoscopic examination. Of the 166 patients who participated in the study, 96 were positive for colonic polyps and 70 were negative. There was a significant increase in risk for adenomas polyps as age increased among males. For females, the step-wise logistic regression indicated that an absence of abdominal pain/cramping (p < .01), a change in stool shape (p < .01), and a history of colorectal polyps (undifferentiated) in first-degree relatives (p < .05) were associated with adenomatous polyps.

Colonic Polyps↗
PubMed2004

Surface normal overlap: a computer-aided detection algorithm with application to colonic polyps and lung nodules in helical CT.

We developed a novel computer-aided detection (CAD) algorithm called the surface normal overlap method that we applied to colonic polyp detection and lung nodule detection in helical computed tomography (CT) images. We demonstrate some of the theoretical aspects of this algorithm using a statistical shape model. The algorithm was then optimized on simulated CT data and evaluated using a per-lesion cross-validation on 8 CT colonography datasets and on 8 chest CT datasets. It is able to achieve 100% sensitivity for colonic polyps 10 mm and larger at 7.0 false positives (FPs)/dataset and 90% sensitivity for solid lung nodules 6 mm and larger at 5.6 FP/dataset.

Algorithms↗
PubMed1986

Single-contrast vs double-contrast barium enema in the detection of colonic polyps.

Radiographic and colonoscopic correlation in 139 patients with 234 colonic polyps compared the sensitivity of single- and double-contrast barium enema. Single-contrast barium enema detected 68 (80%) of polyps, with 72% of polyps under 1 cm and 94% of those 1 cm or over detected. Double-contrast barium enema detected 135 (91%) of 149 polyps, with 88% of polyps under 1 cm and 96% of larger polyps detected. Thus, the double-contrast barium enema was more effective than the single-contrast examination only for detection of polyps under 1 cm. The single-contrast barium enema was more likely performed on patients in poor physical condition and in those over 70 years old. The results suggest that for elderly patients, who may have difficulty in cooperating for a double-contrast enema, a properly performed single-contrast examination is an acceptable option.

Adenoma↗
PubMed1986

Mucosal changes associated with adenomatous colonic polyps.

In order to assess the presence of morphologically recognizable colonic nonneoplastic mucosal alterations that may be associated with adenomatous transformation the authors undertook a retrospective analysis of 984 colonic polyps removed between 1979 and 1983. There were 708 adenomatous and 276 nonadenomatous polyps, all colonoscopically removed. In addition to adenomatous mucosa, three different mucosal patterns were recognized and labeled as transitional, eosinophilic, and, hyperplastic. Each polyp, but not the polyp's shoulder, was scored by two pathologists for the presence of these changes. Analysis of the data (Pearson's chi-square test) demonstrated a strong association between eosinophilic and transitional mucosa as well as between eosinophilic mucosa and adenomas. There was also a strong negative association between both eosinophilic and transitional mucosa and hyperplastic mucosa. On the basis of these data, it is postulated that transitional mucosa, representing a nonspecific reactive mucosal phenomenon, may precede eosinophilic mucosa, which subsequently may represent fertile soil for adenomatous transformation.

Adult↗
PubMed1993

Expression of colorectal carcinoma-associated antigens in colonic polyps.

Immunohistologic techniques were used to study the expression of colorectal carcinoma-associated antigens in colonic polyps and to compare this with expression in the normal colonic epithelium. Forty-nine polyps were studied using monoclonal antibodies to 16 different blood group and differentiation antigens and carcinoembryonic antigen epitopes. With the Lewis(a) antigen and the two epitopes of CEA recognized by 3D6 and COL-4 expression in polyp tissue was the same as that in the normal colon. Five types of alteration of antigen expression in polyps were seen. The blood group antigens A, B, and Lewis(b), which are expressed only on the right side of the normal adult colon, were detected in both neoplastic and nonneoplastic polyps from the distal colon. The Lewis(x) antigen and the antigen epitopes detected by the antibodies COL-12, CA19-9, ME491, and GA73.3 showed an increased frequency of expression in all types of polyps in comparison with the normal colonic epithelium, while H-type 2, ND4, and the antigen epitope detected by CO29.11 showed a slightly decreased frequency of expression in polyp tissue. The X-like antigen which was expressed in only 7% of normal colon specimens showed increased frequency of expression in polyp tissue with significantly greater expression in neoplastic than hyperplastic lesions (P = 0.003). The TAG-72 antigen was detected only in adenomas with severe dysplasia (P = 0.01), correlating well with premalignant histology. These findings have helped us clarify the variation of antigen expression in colonic polyps and allowed us to define which antigens are worthy of further investigation as markers of possible malignant transformation.

ABO Blood-Group System↗
PubMed1976

Colonic polyps: antecedent- or associated-lesions of large bowel cancer.

Many pathologists, gastroenterologists, and oncologists agree that villous (papillary) adenomas of the large bowel are at risk for the development of large bowel cancer. The role of adenomatous polyps (tubular adenomas) in the genesis of large bowel cancer is not a point of agreement. Future studies with molecular biologic techniques of colon polyps and adjacent mucosa and of the colonic mucosa of animals under treatment with colon carcinogens may clarify the role of colon polyps and other factors in the genesis of large bowel cancer. Polyps larger than 1.0 cm should be removed thrugh the proctosigmoidscope or the colonoscope.

Adenocarcinoma↗
PubMed1988

Risk factors and screening techniques in 500 patients with benign and malignant colon polyps. An urban community experience.

The authors have reviewed 13 years of experience with 500 patients who had 1240 polypoid lesions identified at colonoscopy. An analysis of these patients' symptoms, signs, and past histories prior to initial colonoscopy were collated by computer in order to provide useful information to help in early identification of patients with polyps and to define specific risk factors in patients with polypoid cancers (71 patients with 79 cancers). This study shows that the 500 patients with colon polyps, with and without cancer, are similar in all parameters measured. Their symptoms correlated poorly with the pathology or location of the polyp. Frequently unrelated symptoms brought the patient to the attention of their private physician. A significant high-risk group of patients identified were those with prior colon polyps and cancer. A positive family history of colon cancer was not common. Barium enema, the most common examination, was performed in 90 percent of patients and was the first test to diagnose polyps in 54 percent. Flexible sigmoidoscopy, only more recently available and performed in 20 percent of the patients, established a diagnosis of polypoid disease 96 percent of the time. This study supports screening for all adults above 40 years of age with flexible sigmoidoscopy and stool occult blood.

Adult↗
PubMedDate not supplied

Skin tags--a marker for colon polyps?

The frequency of colorectal cancer increased during the first half of the twentieth century, but for the last four decades, it appears to have stabilized. Today, the average American has a 5 percent probability of developing colorectal cancer during a 70-year life span. The majority of cases occur in persons aged greater than 50 years; the incidence increases up to age 75 years, after which there is a decline. Etiology is unknown; however, environment, genetics, and carcinogens have been implicated. Genetic relations of skin tags, colon polyps, and colon cancer are a matter of ongoing research. If such relations could be established, it could provide clinicians with a possible additional marker for persons at increased risk of colorectal adenoma and adenocarcinoma. Two cases are presented with a brief review of the literature.

Age Factors↗
PubMed1998

[Colonic polyps considered unresectable by endoscopy. Removal by combinations of laparoscopy and endoscopy in 65 patients].

OBJECTIVE: To determine to what extent segmental colectomy could be avoided in patients with polyps though to be endoscopically unresectable by using combination laparoscopy and endoscopy. METHODS: Sixty-five patients referred for colonic polyps though to be unresectably by conventional endoscopy were studied. After analysis of the endoscopic findings, endoscopy was performed in a medicosurgical unit when possible, otherwise a surgical procedure was performed consisting of laparoscopy followed by colonoscopy. Therapeutic strategy depended on laparoscopic and endoscopic findings. RESULTS: Segmental colectomy was avoided in 44 patients (67.7%). Among them, 20 were treated by simple endoscopic polyp removal, 12 by laparoscopy-assisted colonoscopic polypectomy, 9 by laparoscopic wedge colonic resection and 3 by colotomy after colonic exteriorization and polyp resection. Laparoscopic or laparoscopy-assisted segmental colectomy was performed in 16. Segmental colectomy by laparotomy was necessary in 5. No complication occurred. CONCLUSION: Segmental colectomy for unresectable colonic polyps could be avoided in more than half of the patients using laparoscopy and colonoscopy combinations.

Adult↗
PubMed1989

Histopathologic and flow cytometric analysis of adenomatous colonic polyps.

We evaluated the histopathology, DNA content, and proliferative activity of colonic polyps independently. Paraffin-embedded specimens were used as source material. In each case, additional sections were cut at 3 microns and stained with hematoxylin-eosin and trichrome for histopathologic analysis. For DNA analysis and measurement of proliferative activity, the polyp parts were dissected and the nonpolypoid tissue was discarded. The study was limited to those specimens that were received in our department in the years 1972 and 1977. Of the 104 polyps that were submitted for flow cytometric analysis, 36 could not be analyzed owing to excessive debris or insufficient nuclei. DNA aneuploidy was identified in 32% of the cases, with a higher value noted in larger polyps and in severely dysplastic polyps, but these values were not statistically significant. Multiple adenomas from the same patient often showed different DNA histograms. When analyzed according to the percentage of cells in S phase, no significant difference was found in proliferative activity of polyps according to DNA content or size of the polyps. These results suggest that the diagnostic significance of aneuploidy and proliferative activity in polyps must be interpreted with caution.

Adenoma↗
PubMed1995

Posttraumatic colonic polyps with skin heterotopia. Report of a case.

A case of posttraumatic colonic polyps with skin heterotopia is reported. A 35-year-old man was the victim of a grenade explosion, which caused evisceration and partial amputation of the right colon. Twenty-five months after the accident, hypochromic anemia developed because of three polyps in the ascending colon. Histology documented the presence of sebaceous glands and keratinized epithelium, suggesting a graft of skin fragments on the colonic mucosa. Such a skin heterotopia has never been reported.

Adult↗
PubMed1989

Colon polyps in the elderly: appropriate primary care follow-up.

The presence of adenomatous polyps in the colon identifies patients at increased risk of colon cancer. Removal of such polyps and undertaking repeated future examinations is proven to diminish subsequent development of the disease. Discussing with the patient, at the time of index colonoscopy, the need for repeat examination and including a note in the patient's medical record are not by themselves adequate measures of obtaining follow-up. A reminder letter mailed directly to the patient shortly before the desired appointment is a highly effective method of obtaining follow-up, when accompanied by information on the importance of repeat colonoscopy.

Aged↗
PubMed1984

Small colonic polyps: a reappraisal of their significance.

With the advent of fiberoptic endoscopy and modern radiographic techniques, the majority of detected polyps are less than 1 cm. During a seven-month period, we studied 140 patients who had radiographically demonstrated colonic polyps that were confirmed by pathologic study. Tissue specimens were obtained by proctoscopy, colonoscopy, or surgery. There were 222 polyps of which 144 (65%) were 1 cm or less in size, with the preponderance (80%) of these being adenomatous. Of the 82 polyps that ranged in size from 6-10 mm, 68 (83%) were adenomas, including one carcinoma and five villous adenomas. Forty-seven (72%) of the diminutive polyps (less than or equal to 5 mm) were adenomatous, including two with atypia. Our results correspond to those of several recent endoscopic studies, reporting that a small colonic polyp is most likely to be adenomatous, and that it possesses the potential for growth and malignant transformation. The detection of small polyps during barium enema examination is thus warranted, particularly in the proximal colon where the majority are adenomatous. The clinical management of polyps is becoming more aggressive, and the removal of even small lesions (less than or equal to 5 mm) is now performed if they are found incidentally during colonoscopy.

Adenoma↗
PubMed1994

Dose de-escalation chemoprevention trial of alpha-difluoromethylornithine in patients with colon polyps.

BACKGROUND: alpha-Difluoromethylornithine (DFMO) is a potent inhibitor of carcinogenesis in experimental animal models. In these animal models, DFMO has been especially active in preventing carcinogen-induced epithelial cancers, including those of the skin, colon, breast, and urinary bladder. Although DFMO is known to exert its diverse biological effects by suppressing intracellular pools of the polyamines putrescine and spermidine, the precise mechanism by which polyamine depletion, induced by DFMO, suppresses carcinogenesis is unknown. PURPOSE: The specific aim of our study was to determine the lowest dose of DFMO that would deplete target tissue (colorectal mucosa) levels of these polyamines in humans who had undergone prior removal of colon polyps while producing minimal toxic effects. METHODS: A dose de-escalation chemoprevention trial of DFMO was conducted in 111 patients (36 female and 75 male) who were in generally good health, aged 39-79, and who had undergone colonoscopy for surgical removal of an adenomatous colon polyp greater than 3 mm within 5 years prior to entering the study. Groups of patients (12-20 patients per group) were orally treated with single, daily doses of DFMO ranging from 3.0 to 0.1 g/m2 for 4 weeks (28 days). Prior to initiation of DFMO treatment and at the end of treatment, six colorectal biopsy specimens were collected from each patient, along with serum samples. All biopsies were performed between 9 AM and noon to avoid possible effects of diurnal variations in laboratory end points. Samples for analysis of plasma DFMO levels were also collected during this time period on the day after the last day of drug administration. RESULTS: DFMO caused a decrease in both putrescine content and the ratio of spermidine to spermine for all dose groups down to 0.25 g/m2. Both putrescine content and the ratio of spermidine to spermine and changes in these parameters as a function of DFMO treatment decreased as a function of donor age. None of the 30 patients receiving either 0.25 or 0.5 g/m2 experienced any clinical ototoxicity in this trial. CONCLUSIONS: DFMO is both safe and effective in reducing colorectal mucosal polyamine contents when it is administered orally to patients at doses as low as 0.25 g/m2 for 28 days. No ototoxicity was observed at doses up to twice this amount. IMPLICATIONS: If DFMO is also found to be effective in suppressing polyamine contents in other target tissues, it may be useful in preventing a wide range of human epithelial cancers, including those of the prostate and breast.

Administration, Oral↗
PubMed2006

An improved electronic colon cleansing method for detection of colonic polyps by virtual colonoscopy.

Electronic colon cleansing (ECC) aims to segment the colon lumen from a patient abdominal image acquired using an oral contrast agent for colonic material tagging, so that a virtual colon model can be constructed. Virtual colonoscopy (VC) provides fly-through navigation within the colon model, looking for polyps on the inner surface in a manner analogous to that of fiber optic colonoscopy. We have built an ECC pipeline for a commercial VC navigation system. In this paper, we present an improved ECC method. It is based on a partial-volume (PV) image-segmentation framework, which is derived using the well-established statistical expectation-maximization algorithm. The presented ECC method was evaluated by both visual inspection and computer-aided detection of polyps (CADpolyp) within the cleansed colon lumens obtained using 20 patient datasets. Compared to our previous ECC pipeline, which does not sufficiently consider the PV effect, the method presented in this paper demonstrates improved polyp detection by both visual judgment and CADpolyp measure.

Algorithms↗