• Biomedical Science Letters
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• v.18 no.4
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• pp.362-368
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• 2012

Enterotoxigenic Bacteroides fragilis (ETBF) is an intestinal commensal bacterium implicated as a risk factor for colon cancer. The key virulence factor is a secreted toxin called B. fragilis toxin (BFT). In this study we used an in vitro bioassay to examine the prevalence of ETBF in colonic washings from patients with colorectal polyps and normal control patients. We found that 9.3% of polyp patients and 10.9% of non-polyp patients harbored ETBF, respectively. A total of nine ETBF clinical isolates were isolated and confirmed to be positive for the BFT gene by PCR analysis and the ability to induce IL-8 secretion in the colonic epithelial cell line HT29/c1. Two of the ETBF clinical strains were characterized further in vitro and in vivo. We found that the two ETBF clinical isolates induced E-cadherin cleavage in HT29/c1 cells and promoted colonic inflammation in C57BL/6 mice. Our results indicate that the prevalence of ETBF in polyp patients were similar in non-polyp patients suggesting that ETBF carriage does not positively correlate to polyp incidence.

• Clinical Endoscopy
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• v.56 no.1
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• pp.119-124
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• 2023

Inflammatory pseudotumor (IPT) is a rare benign tumor of unknown etiology that can occur in almost any organ system. It has neoplastic features such as local recurrence, invasive growth, and vascular invasion, leading to the possibility of malignant sarcomatous changes. The clinical presentations of colonic IPT may include abdominal pain, anemia, a palpable mass, and intestinal obstruction. A few cases of colonic IPT have been reported, but colonic IPT with pedunculated morphology is very rare. Furthermore, since it can mimic malignant polyps, understanding the endoscopic findings of colonic IPT is important for proper treatment. Herein, we present a case of colonic IPT with pseudosarcomatous changes, presenting as a large polyp, mimicking a malignant polyp in the cecum, along with a literature review.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.3159-3161
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• 2013

Aim: We designed this study to investigate the neutrophil lymphocyte ratio as a biomarker in distinguishing colonic polyps which are neoplastic or non-neoplastic. Materials and Methods: One hundred and twenty-five patients with colonic polyps were enrolled into the study. The following data were obtained from a computerized patient registry database: mean platelet volume (MPV), uric acid (UA), platelet count (PC), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT) and the neutrophil to lymphocyte ratio (NLR). Exclusion criteria were active infectious disease, hematological disorders, and malignancies. Colonic polyps divided into two groups as neoplastic polyps (tubular adenoma, villous adenoma, tubulovillous adenoma) and non-neoplastic polyps (hyperplastic polyps, inflammatory pseudopolyps etc). The relationship between colonic polyp type and NLR was evaluated with statistical analysis. Results: There were 67 patients (53.6%) with neoplastic and 58 (46.4%) patients with non-neoplastic polyps. Mean NLRs of neoplastic and non-neoplastic groups were respectively $3.32{\pm}2.54$ and $2.98{\pm}3.16$ (P<0.05). Conclusion: Although sensitivity and specificity are not high, NLR may be used as a biomarker of neoplastic condition of colonic polyps.

• Clinical Endoscopy
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• v.55 no.4
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• pp.540-548
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• 2022

Background/Aims: Colorectal polyps are removed to prevent progression to colorectal cancer. Polyp size is an important factor for risk stratification of malignant transformation. Endoscopic size estimation correlates poorly with pathological reports and several factors have been suggested to influence size estimation. We aimed to gain insight into the factors influencing endoscopic polyp size estimation. Methods: Images of polyps in an artificial model were obtained at 1, 3, and 5 cm from the colonoscope's tip. Participants were asked to estimate the diameter and volume of each polyp. Results: Fifteen endoscopists from three large-volume centers participated in this study. With an intraclass correlation coefficient of 0.66 (95% confidence interval [CI], 0.62-0.71) for diameter and 0.56 (95% CI, 0.50-0.62) for volume. Polyp size estimated at 3 cm from the colonoscope's tip yielded the best results. A lower distance between the tip and the polyp was associated with a larger estimated polyp size. Conclusions: Correct endoscopic estimation of polyp size remains challenging. This finding can affect size estimation skills and future training programs for endoscopists.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.4143-4147
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• 2016

Purpose: We evaluated all PET/CTs acquired for patients without a primary diagnosis of colorectal cancer, and compared results for those who had subsequent colonoscopy within 6 months, to assess the accuracy of FDG PET/CT for detection of incidental pre-malignant polyps and malignant colon cancers. Materials and Methods: Medical records of 9,545 patients who underwent F-18 FDG PET/CT studies over 3.5 years were retrospectively reviewed. Due to pre-existing diagnosis of colorectal cancer, 818 patients were excluded. Of the remainder, 157 patients had colonoscopy within 6 months (79 males; mean age 61). We divided the colon into 4 regions and compared PET/CT results for each region with colonoscopy and histopathologic findings. True positive lesions included colorectal cancer, villous adenoma, tubulovillous adenoma, tubular adenoma and serrated hyperplastic polyp/hyperplastic polyposis. Results: Of 157 patients, 44 had incidental colonic uptake on PET/CT (28%). Of those, 25 had true positive (TP) uptake, yielding a 48% positive predictive value (PPV); 9% (4/44) were adenocarcinoma. There were 23 false positive (FP) lesions of which 4 were hyperplastic polyp, one was juvenile polyp and 7 were explained by diverticulitis. Fifty eight patients had false negative PET scans but colonoscopy revealed true pre-malignant and malignant pathology, yielding 23% sensitivity. The specificity, negiative predictive value (NPV) and accuracy were 96%, 90% and 87%, respectively. The average SUVmax values of TP, FP and FN lesions were 7.25, 6.11 and 2.76, respectively. There were no significant difference between SUVmax of TP lesions and FP lesions (p>0.95) but significantly higher than in FN lesions (p<0.001). The average size (by histopathology and colonoscopy) of TP lesions was 18.1 mm, statistically different from that of FN lesions which was 5.9 mm (p<0.001). Fifty-one percent of FN lesions were smaller than 5 mm (29/57) and 88% smaller than 10 mm (50/57). Conclusions: The high positive predictive value of incidental focal colonic FDG uptake of 48% for colonic neoplasia suggests that colonoscopy follow-up is warranted with this finding. We observed a low sensitivity of standardly acquired FDG-PET/CT for detecting small polyps, especially those less than 5 mm. Clinician and radiologists should be aware of the high PPV of focal colonic uptake reflecting pre-malignant and malignant lesions, and the need for appropriate follow up.

• Clinical Endoscopy
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• v.51 no.6
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• pp.534-540
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• 2018

From dye-assisted conventional chromoendoscopy to novel virtual chromoendoscopy, image-enhanced endoscopy (IEE) is continuously evolving to meet clinical needs and improve the quality of colonoscopy. Dye-assisted chromoendoscopy using indigo carmine or crystal violet, although slightly old-fashioned, is still useful to emphasize the pit patterns of the colonic mucosa and predict the histological structures of relevant lesions. Equipment-based virtual chromoendoscopy has the advantage of being relatively easy to use. There are several types of virtual chromoendoscopy that vary depending on the manufacturer and operating principle. IEE plays distinctive roles with respect to histologic characterization of colorectal polyps and prediction of the invasion depth of colorectal cancers. In addition, the newest models of IEE have the potential to increase adenoma and polyp detection rates in screening colonoscopy.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8351-8358
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• 2016

Electronic cleansing is an image post processing technique in which the tagged colonic content is subtracted from colon using CTC images. There are post processing artefacts, like: 1) soft tissue degradation; 2) incomplete cleansing; 3) misclassification of polyp due to pseudo enhanced voxels; and 4) pseudo soft tissue structures. The objective of the study was to subtract the tagged colonic content without losing the soft tissue structures. This paper proposes a novel adaptive method to solve the first three problems using a multi-step algorithm. It uses a new edge model-based method which involves colon segmentation, priori information of Hounsfield units (HU) of different colonic contents at specific tube voltages, subtracting the tagging materials, restoring the soft tissue structures based on selective HU, removing boundary between air-contrast, and applying a filter to clean minute particles due to improperly tagged endoluminal fluids which appear as noise. The main finding of the study was submerged soft tissue structures were absolutely preserved and the pseudo enhanced intensities were corrected without any artifact. The method was implemented with multithreading for parallel processing in a high performance computer. The technique was applied on a fecal tagged dataset (30 patients) where the tagging agent was not completely removed from colon. The results were then qualitatively validated by radiologists for any image processing artifacts.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2669-2673
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• 2014

Aim: To evaluate the predominant colorectal polyps in the Almadinah region of Saudi Arabia. Materials and Methods: In this iretrospective study, we analyzed pathology reports of colonoscopies performed in King Fahad Hospital, Madinah, Saudi Arabia during the period 2006 to 2013. Data based on patient age, gender, size, site and type of polyps and the degree of dysplasia were analyzed by software SPSS 17 and compared with other published studies from different geographic regions of the world. Results: During these years, 224 patients had colonic polyps, of whom 149 (66.5%) were men and 75 (33.5%) were women. The most common types of polyps were adenomatous (166), followed by hyperplastic polyps (24), juvenile (18), inflammatory (13), lipomatous (2) and one patient with Peutz-Jegher polyps. Tubulovillous adenoma was the commonest adenomatous polyp (102), followed by tubular (41) and villous (23) types. The sigmoid colon was the most commonly involved region (36.6%). Dysplasia was significantly associated with female patients who had large size tubulovillous polyps located in the left colon. Conclusions: The type and distribution of colorectal polyps in Saudi Arabia is very similar to Western countries. Patient gender, and size, histological type and location of polyps are closely related to dysplastic change in colonic polyps.

• Clinical Endoscopy
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• v.56 no.4
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• pp.479-489
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• 2023

Background/Aims: Accurate neoplastic prediction can significantly decrease costs associated with pathology and unnecessary colorectal polypectomies. Narrow-band imaging (NBI) and dual-focus (DF) mode are promising emerging optical technologies for recognizing neoplastic features of colorectal polyps digitally. This study aimed to clarify the clinical usefulness of NBI with and without DF assistance in the neoplastic prediction of small colorectal polyps (<10 mm). Methods: This cross-sectional study included 530 small colorectal polyps from 343 consecutive patients who underwent colonoscopy at the University Medical Center from September 2020 to May 2021. Each polyp was endoscopically diagnosed in three successive steps using white-light endoscopy (WLE), NBI, and NBI-DF and retrieved for histopathological assessment. The diagnostic accuracy of each modality was evaluated with reference to histopathology. Results: There were 295 neoplastic polyps and 235 non-neoplastic polyps. The overall accuracies of WLE, WLE+NBI, and WLE+NBI+NBI-DF in the neoplastic prediction of colorectal polyps were 70.8%, 87.4%, and 90.8%, respectively (p<0.001). The accuracy of WLE+NBI+NBI-DF was significantly higher than that of WLE+NBI in the polyp size ≤5 mm subgroup (87.3% vs. 90.1%, p<0.001). Conclusions: NBI improved the real-time neoplastic prediction of small colorectal polyps. The DF mode was especially useful in polyps ≤5 mm in size.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.13 no.2
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• pp.154-163
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• 2010

Purpose: Colonic polyposis is less common in children than in adults. The clinical data pertaining to colonic polyposis in children are limited. Children with colonic polyposis have complications associated with numerous polyps, malignant transformation of the polyps, and extraintestinal neoplasms. We studied the clinical spectrum, endoscopic characteristics, and histologic findings of colonic polyposis in Korean children. Methods: We reviewed the clinical data of 37 children with multiple colonic polyps between 1987 and 2009. The mean age at the time of diagnosis of colonic polyposis was 8.0${\pm}$3.2 years. Results: Peutz-Jeghers syndrome, juvenile polyposis syndrome, familial adenomatous polyposis (FAP), and lymphoid polyposis was diagnosed in 22, 7, 6, and 2 children, respectively. The most common clinical presentation in children with colonic polyposis was hematochezia. A family history of colonic polyposis was noted in 7 children. The colonoscopic findings of colonic polyposis varied with the size and number of polyps. The majority of polyps were multi-lobulatd and pedunculated in children with Peutz-Jeghers syndrome. The polyps in children with juvenile polyposis syndrome were primarily round and pedunculated. For the children with FAP, the colon was carpeted with small, sessile polyps. There were multiple sessile polyps in the patients with lymphoid polyposis. Surgical polypectomy was performed in 14 children (38%). Intestinal segmental resection was performed in 13 children (35%). Four patients with FAP underwent total colectomy. Four children with Peutz-Jeghers syndrome had extraintestinal neoplasms. No malignant transformation of polyp was identified. Conclusion: Children with colonic polyposis should undergo a careful initial evaluation and require periodic re-evaluation.