Case Report
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jul 6, 2019; 7(13): 1652-1659
Published online Jul 6, 2019. doi: 10.12998/wjcc.v7.i13.1652
Endoscopic submucosal dissection as excisional biopsy for anorectal malignant melanoma: A case report
Shigeo Manabe, Yoshio Boku, Michiyo Takeda, Fumitaka Usui, Ikuhiro Hirata, Shuji Takahashi
Shigeo Manabe, Michiyo Takeda, Fumitaka Usui, Ikuhiro Hirata, Shuji Takahashi, Department of Gastroenterology, Kouseikai Takeda Hospital, Kyoto 600-8558, Japan
Yoshio Boku, Fujita Clinic, 67, Gokiya-cho, Oomiya-dori Shichijo-kudaru, Shimogyo-ku, Kyoto 600-8267, Japan
Author contributions: Manabe S was responsible for the patient, performed endoscopic submucosal dissection, and drafted the manuscript; Boku Y performed endoscopic examination; Takeda M, Usui F, Hirata I and Takahashi S proofread and revised the manuscript; all authors approved the final version of the manuscript.
Informed consent statement: The patient was offered written explanations before the start of the treatment, and she provided consent.
Conflict-of-interest statement: The authors declare that there is no conflict of interest.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
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/
Corresponding author: Shigeo Manabe, MD, Doctor, Department of Gastroenterology, Kouseikai Takeda Hospital, 841-5, Higashi Shiokoji-cho, Shiokoji-dori Nishinotoin-higashiiru, Shimogyo-ku, Kyoto 600-8558, Japan. s-manabe@takedahp.or.jp
Telephone: +81-75-3611351 Fax: +81-75-3617602
Received: March 2, 2019
Peer-review started: March 2, 2019
First decision: March 29, 2019
Revised: April 15, 2019
Accepted: May 2, 2019
Article in press: May 2, 2019
Published online: July 6, 2019
Processing time: 127 Days and 2.8 Hours
Abstract
BACKGROUND

Anorectal malignant melanoma (AMM) is a rare disorder with an extremely poor prognosis. Although there is currently no consensus on the treatment methods for AMM, surgical procedures have been the most common treatment methods used until now. We recently encountered a case of AMM that we diagnosed using endoscopic submucosal dissection (ESD). To our knowledge, this is the first case of ESD for AMM, suggesting that ESD can potentially be a diagnostic and treatment method for AMM.

CASE SUMMARY

A 77-year-old woman visited our hospital with a chief complaint of anal bleeding and a palpable rectal mass. Colonoscopy revealed a 20-mm protruded lesion in the lower rectum. After obtaining biopsy specimens from the lesion, although a malignant rectal tumor was suspected, a definitive diagnosis was not made. Endoscopic ultrasonography revealed tumor invasion into the submucosal layer but not the muscular layer. Therefore, we performed an excisional biopsy using ESD. Immunohistochemical examination of the ESD-resected specimen revealed tumor cells positive for Human Melanin Black-45, Melan-A, and S-100. Moreover, the tumor cells lacked melanin pigment; thus, a diagnosis of amelanotic AMM was made. Although the AMM had massively invaded the submucosal layer and both lymphatic and venous invasion were present, we closely monitored the patient without any additional therapy on the basis of her request. Six months after ESD, local recurrence was detected, and the patient consented to wide local excision.

CONCLUSION

It is suggested that ESD is a potential diagnostic and treatment method for AMM.

Keywords: Endoscopic submucosal dissection; Anorectal malignant melanoma; Endoscopic mucosal resection; Case report

Core tip: For anorectal malignant melanoma (AMM), surgical procedures such as abdominoperineal resection and wide local excision have been the most common treatment methods used until now. We recently encountered a case in which endoscopic submucosal dissection (ESD) was used for an excisional biopsy of AMM. ESD may be effective for an early and accurate AMM diagnosis because the ESD-resected specimen could provide adequate pathological findings. In addition, as the ESD technique can yield a high en bloc resection rate, ESD may effectively treat early-stage AMM. Thus, it is suggested that ESD is a potential diagnostic and treatment method for AMM.