Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 7, 2021; 27(13): 1321-1329
Published online Apr 7, 2021. doi: 10.3748/wjg.v27.i13.1321
Endoscopic diagnosis for colorectal sessile serrated lesions
Toshihiro Nishizawa, Shuntaro Yoshida, Akira Toyoshima, Tomoharu Yamada, Yoshiki Sakaguchi, Taiga Irako, Hirotoshi Ebinuma, Takanori Kanai, Kazuhiko Koike, Osamu Toyoshima
Toshihiro Nishizawa, Hirotoshi Ebinuma, Department of Gastroenterology and Hepatology, International University of Health and Welfare Narita Hospital, Narita 2868520, Japan
Shuntaro Yoshida, Osamu Toyoshima, Department of Gastroenterology, Toyoshima Endoscopy Clinic, Tokyo 1570066, Japan
Akira Toyoshima, Department of Colorectal Surgery, Japanese Red Cross Medical Center, Tokyo 1508935, Japan
Tomoharu Yamada, Department of Gastroenterology, The University of Tokyo, Tokyo 1138655, Japan
Yoshiki Sakaguchi, Kazuhiko Koike, Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 1138655, Japan
Taiga Irako, Department of Internal Medicine, Irako Clinic, Tokyo 1560052, Japan
Takanori Kanai, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Shinjuku-ku 1608582, Tokyo, Japan
Author contributions: Nishizawa T analyzed the data, and wrote the manuscript; Yoshida S performed colonoscopy and collected the data; Toyoshima A contributed to the data interpretation; Yamada T reviewed endoscopic images; Sakaguchi Y, Irako T, and Ebinuma H critically revised the manuscript; Kanai T and Koike K supervised the study; Toyoshima O designed the study, and analyzed the data.
Institutional review board statement: This retrospective study was approved by the Ethical Review Committee of Hattori Clinic on September 4, 2020 (approval no. S2009-U04).
Informed consent statement: Written informed consents were obtained from the participants.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Toshihiro Nishizawa, MD, PhD, Professor, Department of Gastroenterology and Hepatology, International University of Health and Welfare Narita Hospital, 852 Hatakeda, Narita, Chiba, Narita 286-8520, Japan. nisizawa@kf7.so-net.ne.jp
Received: December 31, 2020
Peer-review started: December 31, 2020
First decision: January 27, 2021
Revised: January 29, 2021
Accepted: March 18, 2021
Article in press: March 18, 2021
Published online: April 7, 2021
Abstract
BACKGROUND

Hyperplastic polyps are considered non-neoplastic, whereas sessile serrated lesions (SSLs) are precursors of cancer via the ‘‘serrated neoplastic pathway’’. The clinical features of SSLs are tumor size (> 5 mm), location in the proximal colon, coverage with abundant mucus called the ‘‘mucus cap’’, indistinct borders, and a cloud-like surface. The features in magnifying narrow-band imaging are varicose microvascular vessels and expanded crypt openings. However, accurate diagnosis is often difficult.

AIM

To develop a diagnostic score system for SSLs.

METHODS

We retrospectively reviewed consecutive patients who underwent endoscopic resection during colonoscopy at the Toyoshima endoscopy clinic. We collected data on serrated polyps diagnosed by endoscopic or pathological examination. The significant factors for the diagnosis of SSLs were assessed using logistic regression analysis. Each item that was significant in multivariate analysis was assigned 1 point, with the sum of these points defined as the endoscopic SSL diagnosis score. The optimal cut-off value of the endoscopic SSL diagnosis score was determined by receiver-operating characteristic curve analysis.

RESULTS

Among 1288 polyps that were endoscopically removed, we analyzed 232 diagnosed as serrated polyps by endoscopic or pathological examination. In the univariate analysis, the location (proximal colon), size (> 5 mm), mucus cap, indistinct borders, cloud-like surface, and varicose microvascular vessels were significantly associated with the diagnosis of SSLs. In the multivariate analysis, size (> 5 mm; P = 0.033), mucus cap (P = 0.005), and indistinct borders (P = 0.033) were independently associated with the diagnosis of SSLs. Size > 5 mm, mucus cap, and indistinct borders were assigned 1 point each and the sum of these points was defined as the endoscopic SSL diagnosis score. The receiver-operating characteristic curve analysis showed an optimal cut-off score of 3, which predicted pathological SSLs with 75% sensitivity, 80% specificity, and 78.4% accuracy. The pathological SSL rate for an endoscopic SSL diagnosis score of 3 was significantly higher than that for an endoscopic SSL diagnosis score of 0, 1, or 2 (P < 0.001).

CONCLUSION

Size > 5 mm, mucus cap, and indistinct borders were significant endoscopic features for the diagnosis of SSLs. Serrated polyps with these three features should be removed during colonoscopy.

Keywords: Sessile serrated lesion, Mucus cap, Indistinct borders, Hyperplastic polyp, Endoscopic features, Size

Core Tip: The features of sessile serrated lesions (SSLs) include tumor size > 5 mm, location in the proximal colon, ‘‘mucus cap’’, indistinct borders, cloud-like surface, and varicose microvascular vessels. Our multivariate analysis revealed that size > 5 mm, mucus cap, and indistinct borders were independent predictors for SSLs. The combination of these three features in serrated polyps allowed the diagnosis of SSLs with 75% sensitivity, 80% specificity, and 78.4% accuracy.