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PubMed1980

Metaplastic polyps and polyposis of the colorectum.

Five hundred and fifty-four colorectal metaplastic polyps have been studied histologically. Whilst most lesions were small and sessile, 16.1% measured greater than 0.5 cm in diameter and 0.9% were greater than 1 cm. The larger polyps were frequently pedunculated and occasionally showed a tubulo-villous or villous pattern. A structural similarity between the larger metaplastic polyps and colorectal adenomas is illustrated and the importance of the distinction of metaplastic from dysplastic epithelium in the differentiation of these lesions is stressed. Other unusual features of metaplastic polyps are described. Evidence is given to suggest that males have a greater propensity to develop metaplastic polyps than females. A search for men adenomas, but relatively frequent (20.8%) in juvenile polyps. Finally, seven patients with multiple metaplastic polyps of the colorectum are described, in whom a diagnosis of adenomatous polyposis had been made at some stage in their management. Six of the seven patients were males and the mean age at presentation was 37.4 years. Larger metaplastic polyps were frequent in these cases. The necessity for histological confirmation in all cases of intestinal polyposis is stressed, and the possibility that 'metaplastic polyposis' is a pathological entity is discussed.

Adenoma↗
PubMed1983

Cystic 'hamartomatous' gastric polyps: a disorder of oxyntic glands.

In 1977, Elster et al. described gastric polyps of a new type. These polyps were formed of fundic glandular cysts in otherwise normal gastric mucosa. In this paper a series of 52 cases of this type of polyp are presented. In addition to cysts, polyps contained deformed oxyntic glands and areas where the formation of secondary irregular glands occurred from cysts and from the existing glands. However, all glands and cysts in polyps were composed of normal, but intermixed cells of oxyntic type, suggesting that deranged differentiation of otherwise normal oxyntic glands is the basic mechanism in the pathogenesis of these polyps. Based on these observations, the polyps were considered most likely to be epithelial hamartomas. In agreement with the findings of Elster et al., the present cases showed typical clinical characteristics: three-quarters of patients were females with a peak prevalence in the fifth and sixth decades. Polyps were most often multiple and occurred only in the oxyntic mucosa of the stomach.

Adult↗
PubMed1990

The increased number of epithelial mast cells in nasal polyps and adjacent turbinates is not allergy-dependent.

Respiratory epithelial mast cells are an expression of airway inflammatory processes. Nasal epithelial mast cells are known to be increased in allergic rhinitis and have now been examined in patients with nasal polyps. Metachromatic cell counts (mean +/- standard error) expressed as the sum of large mast cells, atypical mast cells and basophils in epithelial scrapings of the inferior turbinates, assessed after Carnoy's fixation and toluidine blue staining (pH 0.5), were 37.5 +/- 29 in non-allergic normal control subjects (n = 11), 435 +/- 130 in polyp patients who were allergic (n = 18), and 699 +/- 267 in polyp patients who were not allergic (n = 8). Metachromatic cell counts in epithelial scrapings obtained in vivo from nasal polyps of allergic patients (n = 8) were 1769 +/- 962, and 2308 +/- 1544 from polyps of non-allergic patients (n = 5); metachromatic counts were 2089 +/- 633 in epithelial scrapings from excised polyps of allergic patients (n = 14) and 2214 +/- 640 from polyps of non-allergic patients (n = 13). It is concluded that the number of metachromatic cells in the epithelium of nasal polyps and the adjacent nasal mucosa is elevated compared with normal nasal epithelium and the increased number does not depend upon allergy.

Humans↗
PubMed1985

Solitary gastric polyps in the fundic gland area. A histochemical study.

Six solitary gastric polyps in the acid-secreting fundic mucosa were histochemically investigated using the mucin histochemistry, immunoperoxidase method, and silver methods for endocrine cells. Histologically, the polyps were grouped into three types: they largely consisted of either hyperplastic foveolar cells (group 1), normal-appearing fundic gland cells with mild cystic changes (group 2) or hyperplastic fundic gland cells with cystic dilatation (group 3). The presence of parietal cells and mucous neck cells was confirmed in all polyps by the immunoperoxidase method using parietal cell autoantibody and the paradoxical Concanavalin A staining, respectively. Regarding the endocrine component, somatostatin-containing cells, Grimelius-positive argyrophil cells, and Fontana-Masson-positive enterochromaffin cells were scattered in the fundic gland area of the polyps as well as in the surrounding normal-appearing fundic mucosa. Gastrin-containing cells were absent. In one of the group 2 polyps and both group 3 polyps, a varying number of glicentin-containing cells were found among the fundic gland components: In one polyp in group 3, glucagon immunoreactivity was detected in the glicentin-containing cells. These findings suggest that some of the polyps express characteristics of the fetal fundic mucosa, since glicentin and glucagon immunoreactivities in normal human stomach have been detected exclusively in the fetal fundus.

Gastric Fundus↗
PubMed2004

Significance of endometrial polyps detected hysteroscopically in eumenorrheic infertile women.

AIM: To determine if the incidence of small endometrial polyps detected hysteroscopically in an infertile eumenorrheic population differed from that in an apparently fertile eumenorrheic population. Evidence was sought to determine whether removal of such lesions would enhance reproductive performance. METHODS: In a prospective study, 266 consecutive infertile women had undergone complete fertility evaluation. None of the women had experienced any change in their menstrual cycle. They were divided into two groups; 235 infertile patients (group 1) and 31 requesting a reversal of a previous tubal sterilization (group 2). All patients were examined by simultaneous combined laparoscopy and hysteroscopy as part of their routine infertility evaluation. When endometrial polyps were noted they were removed by hysteroscopy and histopathologically examined. Patients in whom the only apparent finding was endometrial polyps were followed up to determine their reproductive outcomes subsequent to removal of the polyps. RESULTS: Of the 224 uterine cavities successfully visualized in the infertile group, 134 were judged to be normal (60%) and 90 were abnormal (40%). Endometrial polyps were noted in 35 patients of group 1 and in one patient of group 2 (P < 0.01). Most polyps were located in the region of the utero-tubal junction and proved to be functional. A 50% pregnancy rate was achieved by hysteroscopic polypectomy. Fertility-related factors in women whose only apparent finding was endometrial polyps before and after hysteroscopy were comparable. CONCLUSION: Diagnostic hysteroscopy should be used routinely in the work-up of infertile woman, even in the presence of eumenorrhea. Persistent functional endometrial polyps, even if small, are likely to impair fertility in this select patient group. Removal of such lesions may improve subsequent reproductive performance.

Adult↗
PubMed2002

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

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

Adenoma↗
PubMed2006

Mismatch repair polymorphisms and colorectal polyps: hMLH1-93G>A variant modifies risk associated with smoking.

BACKGROUND AND AIM: Mutations in the mismatch repair (MMR) enzymes hMLH1 and hMSH6 are known causes of hereditary nonpolyposis colorectal cancer and act by inducing a mutator phenotype characterized by microsatellite instability. The aim of our study was to determine if polymorphisms in the DNA MMR genes hMLH1 and hMSH6 are associated with an increased risk of colorectal polyps, and to evaluate interactions with exposures known to cause DNA damage. METHODS: In a Minnesota-based case-control study of individuals with adenomas (N=401), hyperplastic polyps (N=195), or both adenomas and hyperplastic polyps (N=123) versus polyp-free controls (N=624), we investigated the role of hMLH1-93G>A, hMLH1 I219V, and hMSH6 G39E polymorphisms in increasing the risk of colorectal polyps. Polytomous multivariate logistic regression analysis was used, adjusting for age, sex, body mass index, postmenopausal hormone use, aspirin use, and NSAID use. RESULTS: Overall, no evidence of an association between any of the three polymorphisms or hMLH1 haplotypes and colorectal polyps was observed. However, risk associated with the hMLH1-93A variant differed by smoking: smoking-associated risks were stronger among those with variant -93AA or -93AG genotypes, showing a twofold greater risk of adenoma with >25 pack-years of smoking compared with nonsmokers, and a corresponding eightfold greater risk of hyperplastic polyps (genotype smoking: p-interaction=0.02 for hyperplastic polyps and p-interaction=0.08 for adenomas). CONCLUSIONS: These data are consistent with the observation that smoking is associated with MMR in colorectal neoplasia and suggest that the risk increase with smoking may differ by hMLH1-93G>A genotype.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Comparative study of conventional colonoscopy, chromoendoscopy, and narrow-band imaging systems in differential diagnosis of neoplastic and nonneoplastic colonic polyps.

AIM: To identify the feasibility of the narrow-band imaging (NBI) method compared with that of conventional colonoscopy and chromoendoscopy for distinguishing neoplastic and nonneoplastic colonic polyps. METHOD: This study enrolled consecutive patients who underwent colonoscopy using a conventional colonoscope between January and February 2006 at Chang-Gung Memorial Hospital, Linkou Medical Center, Taiwan. These 78 patients had 110 colorectal polyps. During the procedure, conventional colonoscopy first detected lesions, and then the NBI system was used to examine the capillary networks. Thereafter indigo carmine (0.2%) was sprayed directly on the mucosa surface prior to evaluating the crypts using a conventional colonoscope. The pit patterns were characterized using the classification system proposed by Kudo. Finally, a polypectomy or biopsy was performed for histological diagnosis. RESULTS: Of the 110 colorectal polyps, 65 were adenomas, 40 were hyperplastic polyps, and five were adenocarcinomas. The NBI system and pit patterns for all lesions were analyzed. For differential diagnosis of neoplastic (adenoma and adenocarcinoma) and nonneoplastic (hyperplastic) polyps, the sensitivity of the conventional colonoscope for detecting neoplastic polyps was 82.9%, specificity was 80.0% and diagnostic accuracy was 81.8%, significantly lower than those achieved with the NBI system (sensitivity 95.7%, specificity 87.5%, accuracy 92.7%) and chromoendoscopy (sensitivity 95.7%, specificity 87.5%, accuracy 92.7%). Therefore, no significant difference existed between the NBI system and chromoendoscopy during differential diagnosis of neoplastic and nonneoplastic polyps. CONCLUSION: The NBI system identified morphological details that correlate well with polyp histology by chromoendoscopy.

Adult↗
PubMed1997

High frequency of K-ras mutations in human colorectal hyperplastic polyps.

BACKGROUND: Hyperplastic polyps are common benign colorectal polyps, and are thought to have little association with malignant tumours in the colorectum. However, several reports suggest that some hyperplastic polyps may develop into colorectal neoplasms. AIM: To clarify genetic alterations in colorectal hyperplastic polyps. METHODS: Twenty eight colorectal polyps having serrated components were resected from patients endoscopically. The K-ras gene mutations in codons 12 and 13 were analysed by PCR-RFLP. Intranuclear p53 protein was immunostained by the avidin-biotin complex method. RESULTS: A mutation of the K-ras gene was detected in nine (47%) of 19 hyperplastic polyps, and five (56%) of nine adenomas. p53 protein nuclear accumulation was detected immunohistochemically in two (22%) of nine adenomas, but not in any of the hyperplastic polyps. CONCLUSION: Some hyperplastic polyps may be true neoplastic lesions, and could be precursors of malignant neoplasia.

Adenoma↗
PubMed2002

Colonic polyps: complementary role of computer-aided detection in CT colonography.

PURPOSE: To apply a computer-aided detection (CAD) algorithm to supine and prone multisection helical computed tomographic (CT) colonographic images to confirm if there is any added benefit provided by CAD over that of standard clinical interpretation. MATERIALS AND METHODS: CT colonography (with patients in both supine and prone positions) was performed with a multisection helical CT scanner in 40 asymptomatic high-risk patients. There were two consecutive series of patients, 20 of whom had at least one polyp 1.0 cm in size or larger and 20 of whom had normal colons at conventional colonoscopy performed the same day. The CT colonographic images were interpreted with an automated CAD algorithm and by two radiologists who were blinded to colonoscopy findings. RESULTS: For 25 polyps at least 1.0 cm in size ("large" polyps), sensitivity for detection by at least one radiologist was 48% (12 of 25). The sensitivity of CAD for detecting large polyps was also 48% (12 of 25), but the CAD algorithm detected four of 13 large polyps that were not detected by either radiologist (31%, 95% two-sided CI: 9, 61), increasing the potential sensitivity to 64% (16 of 25). For polyps identifiable retrospectively, sensitivity of CAD was 67% (12 of 18), and sensitivity of the combination of detection with the CAD algorithm or by at least one radiologist was 89% (16 of 18). There were an average of 11 false-positive detections per patient for CAD. CONCLUSION: In this series of patients in whom radiologists had difficulties detecting polyps (compared with sensitivities of 75%-90% reported in the literature), this CAD algorithm played a complementary role to conventional interpretation of CT colonographic images by detecting a number of large polyps missed by trained observers.

Aged↗
PubMed2005

Colorectal polyps: detection with low-dose multi-detector row helical CT colonography versus two sequential colonoscopies.

PURPOSE: To prospectively evaluate the diagnostic accuracy of low-radiation-dose computed tomographic (CT) colonography for detection of colorectal polyps by using two sequential colonoscopies, with the second colonoscopy as the reference standard. MATERIALS AND METHODS: The study was local ethics committee approved, and all patients gave written informed consent. Colonographic images were acquired by using a low-dose multi-detector row CT protocol (effective milliampere-second setting, 10 mAs). Three observers interpreted the CT colonographic data separately and independently by using a two-dimensional technique. Initial conventional colonoscopy was performed by an endoscopist unaware of the CT colonographic findings. Second colonoscopy performed within 2 weeks by a colonoscopist aware of both the CT colonographic and the initial colonoscopic findings served as the reference standard. The sensitivities of CT colonography and initial colonoscopy were calculated on a per-polyp and a per-patient basis. Specificities and positive and negative predictive values also were calculated on a per-patient basis. RESULTS: Eighty-eight patients underwent CT colonography and initial conventional colonoscopy on the same day. Per-polyp sensitivities were 62% and 83% for CT colonography and initial colonoscopy, respectively. Sensitivities for detection of polyps 6 mm in diameter or larger were 86% and 84% for CT colonography and initial colonoscopy, respectively. Initial colonoscopy failed to depict 16 polyps, six of which were correctly detected with CT colonography. For identification of patients with polyps 6 mm in diameter or larger, CT colonography and initial colonoscopy, respectively, had sensitivities of 84% and 90%, specificities of 82% and 100%, positive predictive values of 70% and 100%, and negative predictive values of 91% and 95%. CONCLUSION: Low-dose CT colonography compares favorably with colonoscopy for detection of colorectal polyps 6 mm in diameter or larger, with markedly decreased performance for detection of polyps 5 mm in diameter or smaller.

Aged↗
PubMed2006

CT colonography: influence of 3D viewing and polyp candidate features on interpretation with computer-aided detection.

PURPOSE: To retrospectively determine if three-dimensional (3D) viewing improves radiologists' accuracy in classifying true-positive (TP) and false-positive (FP) polyp candidates identified with computer-aided detection (CAD) and to determine candidate polyp features that are associated with classification accuracy, with known polyps serving as the reference standard. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained; this study was HIPAA compliant. Forty-seven computed tomographic (CT) colonography data sets were obtained in 26 men and 10 women (age range, 42-76 years). Four radiologists classified 705 polyp candidates (53 TP candidates, 652 FP candidates) identified with CAD; initially, only two-dimensional images were used, but these were later supplemented with 3D rendering. Another radiologist unblinded to colonoscopy findings characterized the features of each candidate, assessed colon distention and preparation, and defined the true nature of FP candidates. Receiver operating characteristic curves were used to compare readers' performance, and repeated-measures analysis of variance was used to test features that affect interpretation. RESULTS: Use of 3D viewing improved classification accuracy for three readers and increased the area under the receiver operating characteristic curve to 0.96-0.97 (P<.001). For TP candidates, maximum polyp width (P=.038), polyp height (P=.019), and preparation (P=.004) significantly affected accuracy. For FP candidates, colonic segment (P=.007), attenuation (P<.001), surface smoothness (P<.001), distention (P=.034), preparation (P<.001), and true nature of candidate lesions (P<.001) significantly affected accuracy. CONCLUSION: Use of 3D viewing increases reader accuracy in the classification of polyp candidates identified with CAD. Polyp size and examination quality are significantly associated with accuracy.

Adult↗
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↗
PubMed1985

Distribution of colonic polyps: increased incidence of proximal lesions in older patients.

Several recent studies have shown a proximal shift in the distribution of colonic carcinoma compared to older studies. Because of the association between polyps and cancer, the authors evaluated the distribution of colonic polyps in 3,664 consecutive patients who had a colon examination over a period of 14 months. A total of 967 colorectal polyps were found in 633 patients. In all, 502 polyps (52%) were proximal to the rectosigmoid. Older patients had significantly more right-sided polyps and fewer rectosigmoid lesions. Large polyps occurred more frequently in the right colon, and this was also statistically significant. Gender has no effect on polyp distribution. The authors conclude that the importance of screening for polyps, particularly on the right side of the colon, increases with age.

Adult↗
PubMed2000

Automated polyp detector for CT colonography: feasibility study.

An abdominal computed tomographic scan was modified by inserting 10 simulated colonic polyps with use of methods that closely mimic the attenuation, noise, and polyp-colon wall interface of naturally occurring polyps. A shape-based polyp detector successfully located six of the 10 polyps. When settings that enhanced the edge profile of polyps were chosen, eight of 10 polyps were detected. There were no false-positive detections. Shape analysis is technically feasible and is a promising approach to automated polyp detection.

Colon↗
PubMed2001

Automated polyp detection at CT colonography: feasibility assessment in a human population.

PURPOSE: To test the feasibility of and improve a computer algorithm to automatically detect colonic polyps in real human computed tomographic (CT) colonographic data sets. MATERIALS AND METHODS: Twenty patients with known polyps underwent CT colonography in the supine position. CT colonographic data were processed by using a shape-based algorithm that depicts masses that protrude into the lumen. We studied nine shape criteria and three isosurface threshold settings. Results were compared with those of conventional colonoscopy performed the same day. RESULTS: There were 50 polyps (28 were > or =10 mm in size; 12, 5-9 mm; 10, <5 mm). The sensitivity with optimal settings for detecting polyps 10 mm or greater was 64% (18 of 28). Sensitivity improved to 71% (10 of 14) for polyps 10 mm or greater in well-distended colonic segments. Performance decreased for polyps less than 10 mm, poorly distended colonic segments, and other shape algorithms. There was a mean of six false-positive lesion sites per colon. These sites were reduced 39% to 3.5 per colon by sampling CT attenuation at the lesion site and discarding sites having attenuation less than a threshold. CONCLUSION: Automated detection of colonic polyps, especially clinically important large polyps, is feasible. Colonic distention is an important determinant of sensitivity. Further increases in sensitivity may be achieved by adding prone CT colonography.

Adult↗
PubMed2002

Gallbladder polyps: epidemiology, natural history and management.

Polypoid lesions of the gallbladder affect approximately 5% of the adult population. Most affected individuals are asymptomatic, and their gallbladder polyps are detected during abdominal ultrasonography performed for unrelated conditions. Although the majority of gallbladder polyps are benign, most commonly cholesterol polyps, malignant transformation is a concern. The differentiation of benign from malignant lesions can be challenging. Several features, including patient age, polyp size and number, and rapid growth of polyps, are important discriminating features between benign and malignant polyps. Based on the evidence highlighted in this review, the authors recommend resection in symptomatic patients, as well as in asymptomatic individuals over 50 years of age, or those whose polyps are solitary, greater than 10 mm in diameter, or associated with gallstones or polyp growth on serial ultrasonography. Novel imaging techniques, including endoscopic ultrasonography and enhanced computed tomography, may aid in the differential diagnosis of these lesions and permit expectant management.

Cholecystectomy↗
PubMed2003

[Gastric epithelial polyps. A retrospective study 1995-2000].

OBJECTIVE: The analysis of the endoscopic and histological characteristics of all the gastric epithelial polyps diagnosed through endoscopy in our service during a period of 5 years, and the evaluation of the usefulness of the endoscopic monitoring after polypectomy. PATIENTS AND METHODS: Between January 1995 and January 2000 5,314 high digestive system endoscopies were carried out in the Gastroenterology Service of the Santa María Madre Hospital. Sixty-four gastric epithelial polyps were detected in 18 patients (10 men and 8 women) with a median age of 61.7 years. RESULTS: Sixty-three polyps were removed through endoscopic polypectomy, and one was biopsied because of its size (5 cm), 30 (46.87%) were hyperplastic polyps, 24 (37.5%) presented normal histological characteristics, 8 (12.5%) were adenomas and 2 (3.12%) were polypoid adenocarcinomas. 56.2% measured less than 6 mm and only 6.2% measured more than 11 mm. No patient presented simultaenous gastric adenocarcinoma. Only one complication was observed after the polypectomy, a hemorrhage that was treated successfully with local injection of adrenaline. During the follow-up no case of cancer was detected and the recurrence of the polyp was observed in 2/8 patients with adenoma. CONCLUSIONS: Gastric epithelial polyps are infrequent (0.33% gastroscopies); most of them (93.75%) measure less than 1 cm and they can be removed through endoscopy with safety. In our series, the most frequent histological type was the hyperplastic polyp (43.75%); polypoid adenocarcinoma constituted 3.12% of the cases, one of them with less than 6 mm. Endoscopic follow-up is considered absolutely essential after the polypectomy, especially in adenomatous polyps.

Adult↗