The pathologic measurement of polyp size is preferable to the endoscopic estimate

Background: There is no standardized technique to measure polyp size. Estimation of polyp size at endoscopy is difficult. Polyp size measurement by pathologists would seem to be an accurate alternative, but tissue fixation may alter polyp size. To evaluate methods of determining polyp size, we compared endoscopists' estimates and pathologists' measurements with measurements made by an independent examiner. Methods: Polyps were measured by an independent investigator before and after formalin fixation. The investigator's measurement before fixation (the “gold standard”) was compared with the endoscopists' estimates and the pathologists' measurements. Results: Ten endoscopists removed 61 polyps with a snare in 33 patients: 82% were adenomatous and 72% were pedunculated. Mean size was 0.85 ± 0.6 cm (SD) (range: 0.3 to 3.6 cm, 26% ≥ 1 cm). Polyps remained in formalin for a mean of 239 minutes (46 to 1164 minutes). Polyps neither consistently shrank nor enlarged in formalin (maximum change ± 0.2 cm, r  = 0.99 [p < 0.001]). Interobserver agreement between pathologists' and the investigator's post-formalin measurements showed that 55 of 57 polyps (97%) were within ± 0.3 cm. Endoscopists inaccurately estimated 11 of 56 polyps (20%) (> 0.3 cm difference from the independent examiner). Polyp size was underestimated in three instances (range 0.5 to 0.9 cm) and overestimated in eight (range 0.4 to 0.8 cm). In 5 of 11 instances (46%), this inaccuracy altered polyp size classification across the 1 cm threshold. Results were not dependent on endoscopist, histology, or polyp location. Conclusions: (1) Polyp size is not significantly affected by formalin fixation; 2) Endoscopists' estimates of polyp size are often unreliable; and, when possible, (3) Pathologists' measurements of polyp size should be used in clinical trials and in clinical practice. (Gastrointest Endosc 1997;46:492-6.)     

如何通过内镜活检提高大肠淋巴瘤的诊断水平

大肠淋巴瘤临床表现并无特异性,肠镜检查虽多能发现黏膜病变,但由于组织病理学上多有明显的炎症背景,与炎症浸润的淋巴细胞难以区分。肠镜下溃疡病变为淋巴瘤的常见表现,但由于内镜活检取材局限,常常误诊为克罗恩病或肠结核,不易获得明确诊断。本文从肠道淋巴瘤发生的病理学基础入手,介绍了肠道淋巴瘤内镜下的常见表现和临床诊断线索,强调可疑病变需要大块黏膜剥离活检,借助淋巴瘤的单克隆起源特性,通过病理形态和免疫组化的结合,正确诊断肠道淋巴瘤,从而提高内镜诊断大肠淋巴瘤的水平。     

Quest for the best endoscopic imaging modality for computer-assisted colonic polyp staging

BACKGROUND It was shown in previous studies that high definition endoscopy, high magnification endoscopy and image enhancement technologies, such as chromoendoscopy and digital chromoendoscopy [narrow-band imaging(NBI), iScan] facilitate the detection and classification of colonic polyps during endoscopic sessions. However, there are no comprehensive studies so far that analyze which endoscopic imaging modalities facilitate the automated classification of colonic polyps. In this work, we investigate the impact of endoscopic imaging modalities on the results of computer-assisted diagnosis systems for colonic polyp staging.AIM To assess which endoscopic imaging modalities are best suited for the computerassisted staging of colonic polyps.METHODS In our experiments, we apply twelve state-of-the-art feature extraction methods for the classification of colonic polyps to five endoscopic image databases of colonic lesions. For this purpose, we employ a specifically designed experimental setup to avoid biases in the outcomes caused by differing numbers of images per image database. The image databases were obtained using different imaging modalities. Two databases were obtained by high-definition endoscopy in combination with i-Scan technology(one with chromoendoscopy and one without chromoendoscopy). Three databases were obtained by highmagnification endoscopy(two databases using narrow band imaging and one using chromoendoscopy). The lesions are categorized into non-neoplastic and neoplastic according to the histological diagnosis.RESULTS Generally, it is feature-dependent which imaging modalities achieve high results and which do not. For the high-definition image databases, we achieved overall classification rates of up to 79.2% with chromoendoscopy and 88.9% without chromoendoscopy. In the case of the database obtained by high-magnification chromoendoscopy, the classification rates were up to 81.4%. For the combination of high-magnification endoscopy with NBI, results of up to 97.4% for one database and up to 84% for the other were achieved. Non-neoplastic lesions were classified more accurately in general than non-neoplastic lesions. It was shown that the image recording conditions highly affect the performance of automated diagnosis systems and partly contribute to a stronger effect on the staging results than the used imaging modality.CONCLUSION Chromoendoscopy has a negative impact on the results of the methods. NBI is better suited than chromoendoscopy. High-definition and high-magnification endoscopy are equally suited.     

An animal training model for endoscopic treatment of Zenker's diverticulum

BACKGROUND: Zenker's diverticulum (ZD) is an uncommon disease, which is typically treated surgically. The alternative to surgery is a diverticulotomy, performed endoscopically. Given the rarity of this condition, it is not possible to obtain training. There has been no animal model identified that resembles the disease in human beings. OBJECTIVE: To present an animal model of ZD that resembles the disease in human beings. DESIGN: We prospectively characterized the endoscopy, the radiography, and the histologic anatomy of the pharyngeal diverticulum in the pig. SETTINGS: Domestic pigs scheduled for euthanasia underwent radiography and endoscopy and, after euthanasia, neck dissection of the pharyngeal diverticulum. INTERVENTIONS AND METHODS: Thirteen consecutive animals were studied. Pictures were taken for the endoscopic view, as well as radiographies during barium swallow in 1 pig. The neck region was dissected, and the pharynx and the upper esophagus were extracted. The size of the diverticulum was measured, and the block was fixed in formalin. Fixed specimens were cut in the transverse and coronal axis, and pictures were taken. The septum between the diverticulum and the esophagus was reviewed microscopically. RESULTS: The pharyngeal diverticulum measured an average of 2.7 cm (1.3-5 cm), depending on the size of the pig. From an endoscopic and radiologic perspective, the pig pharyngeal diverticulum is identical to a ZD. The septum contains muscle as well as fibrous tissue and fat. These anatomical characteristics closely resemble the anatomy in human beings. CONCLUSIONS: We believe that we established an animal training model for the endoscopic treatment of ZD.     

Measurement system that improves the accuracy of polyp size determined at colonoscopy

AIM:To assess the accuracy of polyp size using an endoscopic lesion measurement system(ELMS).METHODS:The accuracy of polyp size assessment was compared among measurements acquired by visual estimation,disposable graduated biopsy forceps(DGBF;used as a"scale-plate")and the ELMS.RESULTS:There were 192 polyps from 166 cases included in this study.The mean diameter of the post polypectomy measurement was 0.85±0.53 cm(range:0.2-3.0 cm).The mean diameter by visual estimation was 1.10±0.53 cm,which was significantly different compared to the actual size of the polyp(P0.001).The mean diameters obtained using DGBF(0.87±0.54cm)and ELMS(0.85±0.53 cm)did not significantly differ from the actual size of the polyp.The difference between the measurements from the ELMS and DGBF was not significant.CONCLUSION:Unlike visual estimations at colonoscopy,endoscopic graduated biopsy forceps and the endoscopic lesion measurement system are accurate methods to estimate polyp size.     

Malignant melanoma with metastasis to a colonic polyp

Tumor-to-tumor metastases are rare occurrences. A 75-yr-old male presented with an enlarging axillary mass. Further investigation revealed an adenocarcinoma of the colon and a colonic polyp. Metastatic malignant melanoma was present within the colonic polyp and in axillary lymph nodes. In the polypectomy specimen, the distinctly dimorphic histologic appearance was the best clue to the metastatic nature of the malignant component of the polyp. The diagnosis was confirmed by histochemistry and immunocytochemistry. This is the third reported instance of a colonic polyp acting as the host in a case of tumor-to-tumor metastasis.     

内镜下肠道息肉大小测量方法的研究现状与进展

肠镜筛查和及时的内镜下息肉切除可降低肠道肿瘤的发病率和死亡率。息肉大小的确定对于评估肠道肿瘤的风险以及内镜监测间隔的建议至关重要。内镜医生的主观判断是临床实践中评估息肉大小的普遍方式, 但准确性受学界质疑。本研究总结了目前国内外对肠道息肉大小测量的标准及方法的研究现状, 为临床实践提供参考以期探索出能够适用于临床的测量技术方法。     

Residual stalks of pedunculated adenomas. An underrecognized type of colonic polyp

Variable lengths of stalk of colonic pedunculated adenomas may be left behind at polypectomy. At follow-up endoscopy, a residual stalk is a smooth-surfaced, sessile polyp, without a distinct head, and may be difficult to remove. It may be mistaken endoscopically for either a recurrent adenoma or a polyp missed at the original procedure. Histologically, it has a coat of normal mucosa and a core of submucosa in which recanalized blood vessels, scarring, and hemosiderin deposition (consequences of thermocautery) may be seen. We present four cases illustrating the clinicopathologic problem and the pathologic appearances. One caused clinical concern because of its size and location at the site of former polypectomy. One was histologically confusing and raised the question of a vascular malformation. The third, seen at segmental colectomy after endosocopic biopsy of an adenoma, illustrates the gross appearances. The fourth contained regenerative mucosa and recanalized submucosal blood vessels.     

Use of disposable graduated biopsy forceps improves accuracy of polyp size measurements during endoscopy

AIM: To determine the accuracy of endoscopic polyp size measurements using disposable graduated biopsy forceps(DGBF). METHODS: Gradations accurate to 1 mm were assessed with the wire of disposable graduated biopsy forceps. When a polyp was noted, endoscopists determined the width of the polyp; then, the graduated biopsy forceps was inserted and the largest diameter of the tumor was measured. After excision, during surgery or endoscopy, the polyp was measured using the vernier caliper.RESULTS: One hundred and thirty-three colorectal polyps from 119 patients were studied. The mean diameter, by post-polypectomy measurement, was 0.92 ± 0.69 cm; 83 were 1 cm, 36 were between 1 and 2 cm, and 14 were 2 cm. The mean diameter, by visual estimation, was 1.15 ± 0.88 cm; compared to the actual size measured using vernier calipers, the difference was statistically significant. The mean diameter measured using the DGBF was 0.93 ± 0.68 cm; compared to the actual size measured using vernier calipers, this difference was not statistically significant. The ratio between the mean size estimated by visual estimation and the actual size was significantly different from that between the mean size estimated using the DGBF and the actual size(1.26 ± 0.30 vs 1.02 ± 0.11).CONCLUSION: The accuracy of polyp size estimation was low by visual assessment; however, it improved when the DGBF was used.     

An expanded training program for endosonographers improved self-diagnosed accuracy of endoscopic ultrasound-guided fine-needle aspiration cytology of the pancreas

Abstract

Objective. Rapid on-site evaluation (ROSE) of cytologic adequacy improves the diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). However, on-site advice from a cytotechnologist or cytopathologist is not always available during EUS-FNA. To enhance endosonographers' ability to assess the adequacy of EUS-FNA specimens, we designed an intensive, 2-h interactive training program. The aim of this study was to determine the usefulness of the program. Methods. Four cytological pictures were selected by a trained cytotechnologist and board-certified cytopathologist from each of the seven patients who underwent EUS-FNA for pancreatic mass in Okayama University Hospital. In total, 28 pictures were used in this study. Twenty endosonographers and 14 cytologists with different levels of EUS-FNA experience evaluated cytological pictures independently before and after the training program. Results. Endosonographers' skill in evaluating the adequacy of EUS-FNA specimens was significantly improved after the completion of the training program (p < 0.001). In contrast, almost all cytologists correctly judged the adequacy of the specimens before taking the training program. Conclusions. This intensive, 2-h interactive training program is useful for endosonographers and capable of improving ROSE of EUS-FNA specimens.