Case Report
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Apr 25, 2016; 8(8): 374-377
Published online Apr 25, 2016. doi: 10.4253/wjge.v8.i8.374
Diagnosis of a submucosal mass at the staple line after sigmoid colon cancer resection by endoscopic cutting-mucosa biopsy
Mitsuaki Morimoto, Koji Koinuma, Alan K Lefor, Hisanaga Horie, Homare Ito, Naohiro Sata, Yoshikazu Hayashi, Keijiro Sunada, Hironori Yamamoto
Mitsuaki Morimoto, Koji Koinuma, Alan K Lefor, Hisanaga Horie, Homare Ito, Naohiro Sata, Department of Surgery, Jichi Medical University, Tochigi 329-0498, Japan
Yoshikazu Hayashi, Keijiro Sunada, Hironori Yamamoto, Department of Gastroenterology, Jichi Medical University, Tochigi 329-0498, Japan
Author contributions: Koinuma K revised the manuscript, and is the article guarantor; Lefor AK, Hayashi Y, Sunada K and Yamamoto H revised the manuscript; Sata N approved the final version of the manuscript; all authors contributed to this manuscript.
Institutional review board statement: The patient was treated with approved diagnostic and therapeutic procedures according to generally accepted standards of care.
Informed consent statement: Informed consent was not required in our facility but obtained from the patient for this case report.
Conflict-of-interest statement: None to report.
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:
Correspondence to: Koji Koinuma, MD, Department of Surgery, Jichi Medical University, 3311-1 Yakushiji Shimotsuke, Tochigi 329-0498, Japan.
Telephone: +81-285-587371 Fax: +81-285-443234
Received: November 11, 2015
Peer-review started: November 12, 2015
First decision: December 7, 2015
Revised: January 16, 2016
Accepted: February 14, 2016
Article in press: February 16, 2016
Published online: April 25, 2016

A 48-year-old man underwent laparoscopic sigmoid colon resection for cancer and surveillance colonoscopy was performed annually thereafter. Five years after the resection, a submucosal mass was found at the anastomotic staple line, 15 cm from the anal verge. Computed tomography scan and endoscopic ultrasound were not consistent with tumor recurrence. Endoscopic mucosa biopsy was performed to obtain a definitive diagnosis. Mucosal incision over the lesion with the cutting needle knife technique revealed a creamy white material, which was completely removed. Histologic examination showed fibrotic tissue without caseous necrosis or tumor cells. No bacteria, including mycobacterium, were found on culture. The patient remains free of recurrence at five years since the resection. Endoscopic biopsy with a cutting mucosal incision is an important technique for evaluation of submucosal lesions after rectal resection.

Keywords: Submucosal tumor, Staple line, Endoscopic cutting-mucosa biopsy

Core tip: This case report demonstrates the importance of endoscopic biopsy using a cutting mucosal incision as a diagnostic tool for a submucosal mass that develops next to the staple line after sigmoid colon resection with a double-stapled anastomosis. We feel that these findings will be of special interest to the readers.