Retrospective Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 21, 2017; 23(11): 2037-2043
Published online Mar 21, 2017. doi: 10.3748/wjg.v23.i11.2037
Is endoscopic ultrasonography essential for endoscopic resection of small rectal neuroendocrine tumors?
Su Bum Park, Dong Jun Kim, Hyung Wook Kim, Cheol Woong Choi, Dae Hwan Kang, Su Jin Kim, Hyeong Seok Nam
Su Bum Park, Dong Jun Kim, Hyung Wook Kim, Cheol Woong Choi, Dae Hwan Kang, Su Jin Kim, Hyeong Seok Nam, Department of Internal Medicine, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Gyeongsangnam-do 626-770, South Korea
Author contributions: Park SB and Kim DJ contributed equally to this work; Kim HW designed the study; Choi CW and Kim HW performed the procedures; Kim SJ and Nam HS collected the data; Park SB and Kim DJ wrote and revised the paper; and Kang DH supervised the report.
Institutional review board statement: The study protocol was approved by the Institutional Review Board at the Pusan National University Yangsan Hospital (IRB number 05-2015-043).
Informed consent statement: Patients were not required to give informed consent for study participation because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: We have no financial relationships to disclose.
Data sharing statement: 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: Hyung Wook Kim, MD, PhD, Department of Internal Medicine, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Beomeo-ri, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do 626-770, South Korea. mdkhwook@gmail.com
Telephone: +82-55-3601534 Fax: +82-55-3601536
Received: December 8, 2016
Peer-review started: December 9, 2016
First decision: January 10, 2017
Revised: January 24, 2017
Accepted: February 17, 2017
Article in press: February 17, 2017
Published online: March 21, 2017
Abstract
AIM

To evaluate the importance of endoscopic ultrasonography (EUS) for small (≤ 10 mm) rectal neuroendocrine tumor (NET) treatment.

METHODS

Patients in whom rectal NETs were diagnosed by endoscopic resection (ER) at the Pusan National University Yangsan Hospital between 2008 and 2014 were included in this study. A total of 120 small rectal NETs in 118 patients were included in this study. Histologic features and clinical outcomes were analyzed, and the findings of endoscopy, EUS and histology were compared.

RESULTS

The size measured by endoscopy was not significantly different from that measured by EUS and histology (r = 0.914 and r = 0.727 respectively). Accuracy for the depth of invasion was 92.5% with EUS. No patients showed invasion of the muscularis propria or metastasis to the regional lymph nodes. All rectal NETs were classified as grade 1 and demonstrated an L-cell phenotype. Mean follow-up duration was 407.54 ± 374.16 d. No patients had local or distant metastasis during the follow-up periods.

CONCLUSION

EUS is not essential for ER in the patient with small rectal NETs because of the prominent morphology and benign behavior.

Keywords: Neuroendocrine tumor, Small, Rectal, Endoscopic ultrasonography, Histology, Endoscopy

Core tip: Small rectal neuroendocrine tumors (NETs; ≤ 10 mm) that are confined to the mucosa or submucosa can be managed by endoscopic resection because of their low risk of metastatic spread. According to the 2015 guidelines of the National Comprehensive Cancer Network, when we evaluate rectal NET, endorectal magnetic resonance or endoscopic ultrasonography (EUS) is recommended. However, EUS may not be essential for evaluation of small rectal NET because of its prominent morphology and benign behavior.