Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 28, 2015; 21(20): 6252-6260
Published online May 28, 2015. doi: 10.3748/wjg.v21.i20.6252
Differential diagnosis of benign and malignant branch duct intraductal papillary mucinous neoplasm using contrast-enhanced endoscopic ultrasonography
Hirofumi Harima, Seiji Kaino, Shuhei Shinoda, Michitaka Kawano, Shigeyuki Suenaga, Isao Sakaida
Hirofumi Harima, Seiji Kaino, Shuhei Shinoda, Michitaka Kawano, Shigeyuki Suenaga, Isao Sakaida, Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan
Author contributions: Harima H drafted the manuscript; Kaino S designed the study and helped draft the manuscript; Shinoda S, Kawano M and Suenaga S acquired and analyzed the data; and Sakaida I approved the final manuscript.
Ethics approval: This study was reviewed and approved by the Institutional Review Board of Yamaguchi University Graduate School of Medicine.
Informed consent: In this retrospective study, written informed consent was not provided by the participants, but the documents that explain how the data included in this study would be used were published on the internet.
Conflict-of-interest: None of the authors have been funded by any foundation or other nongovernmental source. There are no financial disclosures from any authors.
Data sharing: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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/
Correspondence to: Hirofumi Harima, MD, Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan. harima@yamaguchi-u.ac.jp
Telephone: +81-836-222241 Fax: +81-836-222240
Received: November 6, 2014
Peer-review started: November 7, 2014
First decision: December 11, 2014
Revised: January 14, 2015
Accepted: January 30, 2015
Article in press: January 30, 2015
Published online: May 28, 2015
Processing time: 204 Days and 16.2 Hours
Abstract

AIM: To elucidate the role of contrast-enhanced endoscopic ultrasonography (CE-EUS) in the diagnosis of branch duct intraductal papillary mucinous neoplasm (BD-IPMN).

METHODS: A total of 50 patients diagnosed with BD-IPMN by computed tomography (CT) and endoscopic ultrasonography (EUS) at our institute were included in this study. CE-EUS was performed when mural lesions were detected by EUS. The diagnostic accuracy for identifying mural nodules (MNs) was evaluated by CT, EUS, and EUS combined with CE-EUS. In the patients who underwent resection, the accuracy of measuring MN height with each imaging modality was compared. The cut-off values to diagnose malignant BD-IPMNs based on MN height for each imaging modality were determined using receiver operating characteristic curve analysis.

RESULTS: Fifteen patients were diagnosed with BD-IPMN with MNs and underwent resection. The remaining 35 patients were diagnosed with BD-IPMN without MNs and underwent follow-up monitoring. The pathological findings revealed 14 cases with MNs and one case without. The accuracy for diagnosing MNs was 92% using CT and 72% using EUS; the diagnostic accuracy increased to 98% when EUS and CE-EUS were combined. The accuracy for measuring MN height significantly improved when using CE-EUS compared with using CT or EUS (median measurement error value, CT: 3.3 mm vs CE-EUS: 0.6 mm, P < 0.05; EUS: 2.1 mm vs CE-EUS: 0.6 mm, P < 0.01). A cut-off value of 8.8 mm for MN height as measured by CE-EUS improved the accuracy of diagnosing malignant BD-IPMN to 93%.

CONCLUSION: Using CE-EUS to measure MN height provides a highly accurate method for differentiating benign from malignant BD-IPMN.

Keywords: Contrast-enhanced endoscopic ultrasonography; Endoscopic ultrasonography; Computed tomography; Branch duct intraductal papillary mucinous neoplasm; Mural nodules

Core tip: Both the presence and the height of mural nodules (MNs) are important for differentiating benign from malignant branch duct intraductal papillary mucinous neoplasm (BD-IPMN). However, no studies have determined the ability of contrast-enhanced endoscopic ultrasonography (CE-EUS) to accurately measure MN height. In this study, we demonstrated that CE-EUS is the optimal imaging modality for measuring MN height. Using CE-EUS to measure MN height improved the accuracy of the differential diagnosis of benign vs malignant BD-IPMN, therefore enabling patients to avoid unnecessary surgery.