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Colorectal polyps: detection with dark-lumen MR colonography versus conventional colonoscopy.

PURPOSE: To prospectively compare dark-lumen magnetic resonance (MR) colonography with conventional colonoscopy in the detection of colorectal polyps. MATERIALS AND METHODS: Local ethical committee approval and informed consent were obtained. One hundred consecutive patients (56 men, 44 women; mean age +/- standard deviation, 67.7 years +/- 14.7; range, 25-82 years) who were referred for conventional colonoscopy from January 2003 to January 2004 underwent MR colonography and conventional colonoscopy after standard precolonoscopic bowel cleansing. Colonoscopy was performed immediately after MR colonography. For MR colonography, the colon was filled with approximately 2000 mL of tap water. Imaging was performed with a 1.5-T MR unit with patients in the prone position. A T1-weighted three-dimensional volumetric interpolated breath-hold sequence was performed before and 75 seconds after intravenous administration of 0.2 mmol gadobenate dimeglumine per kilogram of body weight. Results of MR colonography were analyzed on a per-polyp and per-patient basis. Findings at colonoscopy were used as the reference for determining accuracy, sensitivity, specificity, and positive and negative predictive values of MR colonography. RESULTS: Of 100 patients recruited for study, 92 (52 men, 40 women; mean age, 61.5 years +/- 14.5; range, 25-82 years) underwent complete MR and conventional colonoscopy examinations. Forty-three of the 92 patients (47%) had normal findings at conventional colonoscopy. In the other 49 patients (53%), conventional colonoscopy depicted 107 polyps (82 adenomas, 25 hyperplastic polyps) and seven carcinomas. At per-polyp analysis, sensitivity of MR colonography in the detection of adenomatous polyps was 100% for polyps at least 10 mm in diameter and 84.2% for polyps 6-9 mm in diameter. At per-patient analysis, the accuracy of MR colonography was 93.1% (sensitivity, 89%; specificity, 96%) if detection of adenomatous polyps of all sizes was considered. CONCLUSION: Dark-lumen MR colonography is a promising modality with high accuracy for detecting colorectal polyps larger than 5 mm in diameter.

Adult↗

Causes of errors in polyp detection at air-contrast barium enema examination.

PURPOSE: To retrospectively determine the cause of errors in air-contrast barium enema (ACBE) examination for detection of polyps 6 mm or larger. MATERIALS AND METHODS: The study had institutional review board approval. Informed consent was waived for this HIPAA-compliant study. ABCE findings in 41 subjects with 56 missed polyps were evaluated by two radiologists to determine if the cause of errors was perceptual or technical. A comparison was made between total number of polyps in the proximal and distal colon and those missed at each location (Fisher exact test). The 288 ACBE examinations were assessed on a scale of 0-4 (0, excellent; 4, very poor) for six colonic segments (paired t test). RESULTS: Of 17 polyps 1 cm or larger not detected in 15 subjects, 11 (65%) were missed because of technical errors and six (35%) because of perceptual errors. Eight (72%) technical and four (67%) perceptual errors occurred proximal to the splenic flexure. One 3.5-cm cecal carcinoma was not diagnosed prospectively (perceptual error). Of 39 6-9-mm polyps not detected in 26 subjects, 35 (90%) were missed because of technical errors and four (10%) because of perceptual errors. Eighty percent of technical and 75% of perceptual errors were in the proximal colon. When the proportion of polyps in the proximal and distal colon was compared, 22 (63%) of 35 polyps in the distal colon and 15 (26%) of 58 in the proximal colon were detected (P = .0009). There were no detectable differences in the quality of studies in subjects whose polyps were detected and subjects whose polyps were missed (P > .05). CONCLUSION: Technical errors were more common than perceptual errors. The majority of missed polyps were in the proximal colon. Detection rates of polypoid lesions might increase if the quality of ACBE examination can be improved, especially in the proximal colon.

Adult↗

Small simulated polyps in pig colon: sensitivity of CT virtual colography.

PURPOSE: The authors evaluated computed tomographic (CT) virtual colography for the detection of simulated polyps under ideal conditions, as well as the effects on lesion conspicuity of (a) collimation, (b) table pitch, and (c) orientation of the colon lumen with respect to the gantry. MATERIALS AND METHODS: Pig colon was resected and cleansed, and polyps with diameters of 3, 7, and 10 mm were created. Each specimen was scanned with collimation of 5 and 7 mm and table pitch of 1.0, 1.6, and 2.0 at angles of 0 degrees, 45 degrees, and 90 degrees to the gantry. The initial two-dimensional (2D) images were reconstructed at 1-mm intervals (2D reconstructions), from which three-dimensional (3D) virtual colography images were generated. Polyp conspicuity on the initial and reconstructed 2D images and the 3D reconstructions was evaluated on a three-point scale: 0 = polyp not depicted, 1 = polyp faintly depicted, and 2 = polyp clearly depicted. RESULTS: The 10-mm-diameter polyp was clearly depicted (grade 2 conspicuity) on every initial and reconstructed 2D image and 3D reconstruction without regard to collimation, table pitch, or angle to the gantry. The 7-mm-diameter polyp was clearly depicted (grade 2 conspicuity) on every initial and reconstructed 2D image, but conspicuity on 3D reconstructions varied as the imaging parameters varied. The 3-mm-diameter polyp was faintly depicted (grade 1 conspicuity) on the initial and reconstructed 2D images and 3D reconstructions, but conspicuity varied on the 3D reconstructions as the imaging parameters varied. CONCLUSION: CT virtual colography helped detection of small mucosal polyps regardless of the angle of the colon lumen to the gantry at which they were obtained.

Animals↗

Display modes for CT colonography. Part I. Synthesis and insertion of polyps into patient CT data.

PURPOSE: To develop and validate a method for the insertion of digitally synthesized polyps into computed tomographic (CT) images of the human colon for use as ground truth for evaluation of virtual colonoscopy. MATERIALS AND METHODS: Spiral CT simulator software was used to generate 10 synthetic polyps in various configurations. Additional software was developed to insert these polyps into volume CT scans. Ten polyps in eight patients were selected for comparison. Three radiologists evaluated whether two-dimensional (2D) CT images and three-dimensional (3D) volume-rendered CT images showed synthetic or real polyps. RESULTS: Edge-response profiles and noise of simulated polyps matched those of native polyps. Frequency distributions of reviewers' responses were not significantly different for synthetic versus real polyps in either 3D or 2D images. Responses were clustered around the response of "unsure" if lesions were real or synthetic. Receiver operating characteristic curves had areas of 0.54 (95% CI = 0.39, 0.68) for 3D and 0.39 (95% CI = 0.25, 0.53) for 2D images, which were not significantly different from random guessing (P = .70 and .28 for 3D and 2D images, respectively). CONCLUSION: Synthetic polyps were indistinguishable from real polyps. This method can be used to generate ground truth experimental data for comparison of CT colonographic display and detection methods.

Adult↗

DNA repair polymorphisms and risk of colorectal adenomatous or hyperplastic polyps.

Genetic variability in DNA repair genes may contribute to differences in DNA repair capacity and susceptibility to cancer, especially in the presence of exposures such as smoking. In a Minnesota-based case-control study of cases with only adenomatous polyps (n = 384), only hyperplastic polyps (n = 191), or both types of polyps (n = 119) versus polyp-free controls (n = 601), we investigated the role of polymorphisms in the DNA repair genes O(6)-methylguanine methyltransferase (MGMT; p.L84F and p.I143V), XPD (p.D312N and p.K751Q), and XPG (p.D1104H). MGMT polymorphisms were not associated with polyp risk. Overall, a homozygous variant XPD-combined genotype was associated with an increased risk of adenomatous polyps [odds ratio (OR), 1.57; 95% confidence interval (95% CI), 1.04-2.38] and an XPGHH1104 genotype with a decreased risk of hyperplastic polyps (OR, 0.36; 95% CI, 0.13-0.98). However, age stratification showed that the XPD association was present only in subjects >/=60 years old (OR, 3.77; 95% CI, 1.94-7.35), whereas the XPG association was observed largely in subjects <60 years old (OR, 0.20; 95% CI, 0.05-0.91). Smokers did not have a significantly increased risk of adenomatous polyps in the absence of synchronous hyperplastic polyps, except for subjects with a homozygous variant XPD genotype or a homozygous wild-type XPG genotype (OR, 3.93; 95% CI, 1.68-9.21 and OR, 1.59; 95% CI, 1.01-2.50, respectively). Smoking was associated with a statistically significant 2.5- to 6-fold increased risk of hyperplastic polyps for individuals with most of the DNA repair genotypes. However, no substantial increase was observed among individuals who were homozygous variant for XPG (1104HH; OR, 1.38; 95% CI, 0.25-7.65). Our data suggest that polymorphisms in DNA repair genes may be risk factors for colorectal neoplasia and that they may exacerbate the effects of exposures to carcinogens.

Adenoma↗

Expression profile of immune-associated genes in nasal polyps.

OBJECTIVES: We performed this study to investigate the expression profile of immune-associated genes and to probe the role of related genes in the immune pathogenesis of nasal polyps. METHODS: Microarray analysis was used to find the expression profile of 491 immune-associated genes in nasal polyps. In validation studies, immunohistochemical staining and Western blot analysis were used to detect interleukin (IL)-17 and IL-17 receptor (IL-17R) in nasal polyps and controls. RESULTS: Eighty-seven genes were differentially expressed in the immune-associated gene profile of nasal polyps, and 15 genes showed differential expression in both chips. In nasal polyp tissues, IL-17 was expressed mainly in the cytoplasm of plasma cells and to a lesser degree in the prickle cell layer of the epithelium and the acinus of the serous gland. In turbinates, IL-17 was also expressed in the same location, but the expression of IL-17 in nasal polyps and that in turbinates differed significantly (p < .05). Both IL-17 and IL-17R displayed specific bands in nasal polyps and turbinates, but the bands of IL-17 and IL-17R in nasal polyps were stronger than those in turbinates. CONCLUSIONS: The differentially expressed genes in immune-associated gene chips will provide clues about, and a theoretical foundation for, the pathogenesis of nasal polyps. Furthermore, IL-17 may play an important role in the occurrence of nasal polyps by overexpression.

Adult↗

Accumulation of interferon gamma-producing TH1 helper T cells in nasal polyps.

We investigated the mechanisms involved in the formation of nasal polyps by examining T-cell clones and their production of soluble mediators in nasal polyps. Recently, the allergic origin of nasal polyps has been challenged. To study this question we characterized T cells from polyp tissue of allergic individuals in terms of their cytokine pattern. Nasal polyp T cells were cloned from allergic individuals undergoing polypectomy. Polyp tissue was dispersed enzymatically, and T cells were stimulated with mitogen and interleukin-2. Control T cells were obtained from peripheral blood of nonallergic donors. Cytokine production of interleukin-4 and interferon was then determined by indirect enzyme-linked immunosorbent assay tests. Polyp T-cell clones were found to produce high interferon but low interleukin-4 levels that were not significantly different from control peripheral blood T-cell clones. In addition, immunoglobulin production by dispersed polyp tissue was investigated. Immunoglobulin levels were higher in polyp tissues than in serum with immunoglobulin A predominating. These results suggest that the inflammatory reaction in nasal polyps is different than that seen in a typical type I hypersensitivity response.

Adult↗

Cold snare excision is a safe method for diminutive colorectal polyps.

Cold snare excision (CSE) has proved to be an effective method for the destruction of diminutive polyps of the colon and rectum. We investigated the correlation between polyp size and bleeding time at the resected end after CSE, and also an appropriate measuring method using CSE. Eighty patients with single polyps were examined. Each polyp was identified as being 5 mm in diameter or smaller using the open-biopsy forceps technique (OBFT). The size of the polyp was calculated using our measuring system (SMS). Of the polyps identified as being 5 mm in diameter or less using OBFT, 15% were 6 mm or more using the SMS. CSE was performed for each polyp, and the time taken for the hemostasis (bleeding time of the CSE; BTCSE) was determined. In seventy-seven polyps that were 6 mm or smaller in SMS, a correlation was noted between SMS and BTCSE. In three polyps that were 7 mm or more by SMS, hemostasis took 10 min or more after CSE, and required electrocoagulation. These results suggest that CSE is a safe method for the removal of polyps determined to be 6 mm in diameter or smaller using the SMS.

Aging↗

Tobacco smoking as a risk factor for colon polyps.

BACKGROUND: Data from a cancer screening project among pattern makers were used to evaluate the association between tobacco smoking and prevalence of colon polyps. METHODS: From 1981-1983, 549 White men were examined by flexible sigmoidoscopy and completed self-administered questionnaires including smoking histories. RESULTS: One or more colon polyps were detected in 76 men. Standardized prevalence rates (SPR) for polyps increased by smoking category (never smoked = 0.094; ex-smokers = 0.118, current smokers = 0.214) and by cigarettes per day, years of smoking, and pack-years among both current and ex-smokers. Both adenomatous and hyperplastic polyps showed an association with smoking while other types of polyps and polyps with unspecified histology did not. The risk associated with smoking was greater for polyps greater than one centimeter in diameter. An interaction with occupational exposures was suggested by a greater increase in the SPR for polyps among current smokers employed as pattern makers for more than 10 years than among current smokers similarly employed for 10 years or less. CONCLUSIONS: Since at least some colon polyps are considered precursor lesions to colon cancer, one of the most common cancers in the United States, this report suggests that the possible link between colon polyps and smoking deserves further evaluation.

Adult↗

Hereditary factor for nasal polyps.

The purpose of this study is to determine whether a hereditary factor exists for nasal polyps. Fifty patients (27 male, 23 female; age range 14-86 years) had a personal history of nasal polyps. These were confirmed by physician reports, polypectomy pathology reports, or direct visualization. These 50 patients were questioned concerning the existence of a familial history (parents, siblings, or children) of nasal polyps. A control group of 30 patients without nasal polyps was obtained by matching sex, age, personal history of atopy, and allergy skin test results to patients with a personal history of nasal polyps. Familial history of nasal polyps was obtained from the control group by direct interview. Seven of 50 (14%) of the group with nasal polyps had a familial history of nasal polyps. Of those seven, three patients had more than one immediate family member with a positive family history (two patients with two family members (sister, mother; 2 sisters) and one patient with three family members (3 brothers)). Among the control group, 0 of 30 (0%) had a familial history of nasal polyps. This difference is statistically significant (P value is 0.0414). This study suggests that there exists a hereditary factor for development of nasal polyps.

Adolescent↗

Mixed colorectal polyps. An immunohistologic and mucin-histochemical study.

The morphology of mixed colorectal polyps was analysed. Thirteen such polyps were found out of 2700 colorectal polyps (0.5%). Histology showed a spectrum of hyperplastic crypts from almost pure goblet cell population (two polyps) to hypermature serrated epithelium with scanty goblet cells (seven polyps). Tubular adenomas occurred in 12 polyps, and a tubulovillous adenoma was found in the largest polyp. Moderate dysplasia was seen in the five large polyps. The border between neoplastic and hyperplastic cells was usually sharp. Mucin histochemistry showed similarities between the mixed polyps and colorectal carcinomas--namely, the reduction/absence of sialomucin in both mature hyperplastic crypts and adenomatous glands. The expression of carcinoembryonic antigen within the hyperplastic crypts and within the neoplastic crypts showing moderate dysplasia was similar to that seen in colorectal carcinomas, whereas it was normal within the neoplastic crypts with low-grade dysplasia. IgA was reduced or absent in both components. Blood group antigen was found only within the adenomatous component of the largest polyp showing also moderate dysplasia.

Adenoma↗

Giant fibrovascular polyp of the hypopharynx: surgical treatment with the biappoach.

Fibrovascular polyps of the esophagus and hypopharynx are benign tumors of the upper digestive tract. The majority of these polyps are located in the upper part of the esophagus but the hypopharyngeal fibrovascular polyps are only rarely seen. Most of them are surgically treated and this is usually done through a cervical incision, although some of them have been removed endoscopically. The authors report here on a case of a 63-yr-old-man with a giant fibrovascular polyp of the hypopharynx that extended into the stomach; this polyp was removed through simultaneous transcervical and transabdominal approaches because of the huge size of the polyp. The man presented with progressive dysphagia of 1 yr duration. The preoperative assessment revealed a giant polyp arising from the left arytenoid and extending into the stomach. The dimension of the polyp was about 26 x 10 x 4 cm. The complete resection of the polyp with the simultaneous transcervical and transabdominal approaches was successful, and it was diagnosed as a fibrovascular polyp. The patient has been followed up without any recurrence for 6 month postoperatively.

Deglutition Disorders↗

Histologic characteristics of gastric polyps in Korea: emphasis on discrepancy between endoscopic forceps biopsy and endoscopic mucosal resection specimen.

AIM: To investigate histological characteristics of gastric polyps in the Korean population. METHODS: We reviewed endoscopic photographs and medical records of patients with gastric polyps who underwent endoscopic mucosal resection from April 1996 through February 2003. RESULTS: A total of 85 gastric polyps from 74 patients were reviewed. Male-to-female ratio was 1:1.96. Mean age was 59.9 +/- 10.8 years. Multiple polyps were observed in 10.8%. Gastric polyps occurred most frequently in the antrum (58.8%). Pathological results on resected specimens were as follows: tubular adenoma 45.9%, hyperplastic polyp 31.8%, inflammatory polyp 9.4%, hamartoma 3.5%, fundic gland polyp 2.4%, tubulovillous adenoma 2.4%, adenocarcinoma 2.4%, dysplasia 1.1%, and mucosal pseudolipomatosis 1.1%. Discrepancy rate between endoscopic biopsy and pathology of resected specimens was 27.1%. There was no relationship between the size of the polyp and concordance rate. CONCLUSION: There is considerable discrepancy in histologic findings between endoscopic forceps biopsy and resected specimens. Approaches to review of the histology of an entire polyp should be performed, especially when an adenoma is suspected.

Aged↗

Endoscopic banding ligation can effectively resect hyperplastic polyps of stomach.

AIM: Bleeding and perforation are the major and serious complications associated with endoscopic polypectomy. To develop a safe and effective method to resect hyperplastic polyps of the stomach, we employed rubber bands to strangulate hyperplastic polyps and to determine the possibility of inducing avascular necrosis in these lesions. METHODS: Forty-seven patients with 72 hyperplastic polyps were treated with endoscopic banding ligation (EBL). On 14 days after endoscopic ligation, follow-up endoscopies were performed to assess the outcomes of the strangulated polyps. RESULTS: After being strangulated by the rubber bands, all of the polyps immediately became congested (100%), and then developed cyanotic changes (100%) approximately 4 minutes later. On follow-up endoscopy 2 weeks later, all the polyps except one had dropped off. The only one residual polyp shrank with a rubber band in its base, and it also dropped off spontaneously during subsequent follow-up. No complications occurred during or following the ligation procedures. CONCLUSION: Gastric polyps develop avascular necrosis following ligation by rubber bands. Employing suction equipment, EBL can easily capture sessile polyps. It is an easy, safe and effective method to eradicate hyperplastic polyps of the stomach.

Female↗

A study of colorectal polyps.

OBJECTIVE: To determine various features of colorectal polyps and to evaluate the safety of colonoscopic polypectomy. DESIGN: Case series. PLACE AND DURATION OF STUDY: The Department of Gastroenterology and Hepatology, Federal Postgraduate Medical Institute, Shaikh Zayed Hospital, Lahore, from January 1987 to January 2004. PATIENTS AND METHODS: This study was based on data analysis of 393 patients who underwent colonoscopic polypectomy at our institution during 17 years from January 1987 to January 2004. Presenting complaints of patients were noted. Polyps were evaluated in terms of size, site, number and histopathology. RESULTS: Among 393 patients, 268 were male and 125 female. Presenting complaints were bleeding per rectum in 339 patients, diarrhea with blood in 34 and without blood in 6 patients, and lower abdominal pain in 12 patients. Two patients were being investigated for iron deficiency anemia. Two hundred and sixty-four patients had juvenile polyps, 39 had adenomatous polyps, 39 hyperplastic polyps, 39 inflammatory polyps, 3 malignant polyps and 2 patients had familial polyposis. Histopathological reports were not available in 7 patients. Size of the polyps ranged from 0.3 cm to 3.0 cm. Left colon was involved in 353 patients, transverse colon in 15, right colon in 8 patients and diffuse involvement of colon found in 17 patients. Bleeding following polypectomy occurred in 2% of the patients. No other procedure related complication occurred. CONCLUSION: Juvenile polyps were the commonest variety of polyps in our study. Colonoscopic polypectomy has very low complication rate.

Colonic Polyps↗

Removal of endometrial polyps by use of grasping forceps and curettage after diagnostic hysteroscopy.

PURPOSE OF INVESTIGATION: To determine the therapeutic efficacy of the use of gall stone forceps and curettage in endometrial polyps removal, after their detection with diagnostic hysteroscopy. METHODS: From 1997 to 2001, we conducted a prospective study in 53 patients who presented at our department for menstrual disorders, infertility problems or postmenopausal bleeding and in whom endometrial polyps were detected by hysteroscopy. All patients received general anesthesia and after hysteroscopic detection of the polyps' location, their removal was attempted by use of Desjardins gall stone forceps and curettage. Immediately after the procedure, a second hysteroscopy was performed in order to detect remnants of the polyps. RESULTS: Fifty patients presented with only one polyp, two with two polyps and one with three polyps. The mean diameter of the polyps ranged from 0.5 to 3 cm. The hysteroscopic appearance of all polyps was not suggestive of malignancy. During the second hysteroscopy we found parts or whole polyps in five and two cases, respectively, accounting for a therapeutic success of 86.8%. The hospitalization time for all patients was 24 hours and occurred no intraoperative or postoperative complications. CONCLUSION: Our method seems to be safe, with low cost and sufficient therapeutic outcome and could be used in hospitals with availability of diagnostic hysteroscopy only.

Adult↗

[Two cases of paranasal sinusitis with choanal polyp in children].

Patients with choanal polyp often suffer from maxillary sinusitis of the same side. Hence, Caldwell-Luc operation in addition to polypectomy has been recommended for the treatment of choanal polyp. Choanal polyp occurs more frequently in children with nasal polyp(s) than in adults with nasal polyp(s). For this reason, it is preferable to perform surgery so as to preserve the maxillary sinus as much as possible. The authors surgically treated two children with choanal polyp. A 12-year-old girl had a choanal polyp arising from the posterior portion of the middle turbinate and received an osteoplastic maxillary operation and functional endoscopic sinus surgery (FESS). The other, a 13-year-old girl, with an antro-choanal polyp underwent FESS only. One year after surgery, both patients showed no recurrence of polyp and had recovered an aerated maxillary sinus cavity covered with normal mucous membrane. Based on the experiences of these two cases, FESS appears to be very helpful in treating children with choanal polyp and paranasal sinusitis.

Adolescent↗

[Expression and distribution of aquaporin-2 in nasal polyps].

OBJECTIVE: To study the distribution and expression of aquaporion-2 (water channel protein; AQP-2) in nasal polyps and to evaluate the role of AQP-2 in the formation of nasal polyps. METHODS: Eleven samples of normal inferior turbinates and forty-six samples of nasal polyps were used. In the group of nasal polyps, there were ten cases of type II phase 1, twelve type II phase 2, ten type II phase 3 and fourteen type III. The expression of AQP-2 in both groups was studied with immunohistochemical technique. RESULTS: 1. Both the number of AQP-2 positive cells and the area density in the epithelial cell layer from nasal polyps were higher than those from inferior turbinates (P < 0.01, P < 0.05 respectively); In the group of nasal polyps, the area density from type III, type II phase 2 and type II phase 3 was significantly higher than that from type II phase 1 (P < 0.05); 2. Both the number of AQP-2 positive cells and the area density in the subepithelial tissue from type III, type II phase 2 and type II phase 3 nasal polyps were higher than those from type II phase 1 nasal polyps and inferior turbinates(P < 0.05), whereas the difference between the latter two was not significant(P > 0.05). CONCLUSION: The high expression of AQP-2 protein in nasal polyps may contribute to the genesis and development of nasal polyps.

Adolescent↗