Case Report
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jun 6, 2019; 7(11): 1337-1343
Published online Jun 6, 2019. doi: 10.12998/wjcc.v7.i11.1337
Multiple synchronous anorectal melanomas with different colors: A case report
Yan-Tao Cai, Li-Chen Cao, Chen-Fang Zhu, Feng Zhao, Bao-Xing Tian, Shan-Yu Guo
Yan-Tao Cai, Li-Chen Cao, Chen-Fang Zhu, Feng Zhao, Bao-Xing Tian, Shan-Yu Guo, Department of General Surgery, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
Author contributions: Cai YT and Cao LC contributed equally to this work; Cai YT and Guo SY designed the study; Zhu CF, Zhao F, Tian BX, and Guo SY performed the surgery; Cao LC and Zhu CF performed postoperative follow-up; Cai YT and Cao LC wrote the manuscript; Guo SY revised the manuscript; all authors read and approved the final manuscript.
Informed consent statement: Written informed consent was obtained from the patient and her relatives.
Conflict-of-interest statement: All the authors have no conflicts of interest to declare.
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: Shan-Yu Guo, MD, PhD, Chief Doctor, Department of General Surgery, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, No. 639, Zhizaoju Road, Huangpu District, Shanghai 200011, China. guoshyu1@163.com
Telephone: +86-21-23271699
Received: January 24, 2019
Peer-review started: January 25, 2019
First decision: January 30, 2019
Revised: February 19, 2019
Accepted: March 16, 2019
Article in press: March 16, 2019
Published online: June 6, 2019
Abstract
BACKGROUND

Anorectal melanoma (AM) is an extremely rare malignant tumor originating from anorectal melanocytes with a poor prognosis. AM has been reported to have a much lower incidence than cutaneous or choroid melanoma, accounting for 0.4%-1.6% of all melanomas.

CASE SUMMARY

We report a 76-year-old female patient diagnosed with anorectal malignant melanoma by colonoscopy and biopsy. Intraoperative examination revealed two distinct anorectal tumors, one melanotic and another amelanotic, as well as two pigmented mucosal zones at the dentate line level. Abdominal perineal resection was performed. A pathological report confirmed all four lesions to be melanomas. Postoperatively, we followed an immunotherapy protocol targeting PD-1 (nivolumab). The patient had 24 mo of disease-free follow-up upon completion of nivolumab treatment.

CONCLUSION

This is the first reported case presenting coexistence of pigmented and unpigmented AMs in the same patient.

Keywords: Anorectal melanoma, Melanotic, Amelanotic, Synchronous, Case report

Core tip: Anorectal melanoma (AM) is an extremely rare malignant tumor. We report a 76-year-old female patient diagnosed with anorectal malignant melanoma by colonoscopy and biopsy. Intraoperative examination revealed two distinct anorectal tumors, one melanotic and another amelanotic. Two satellite melanotic implantations were also found in the near mucosal area. This is the first reported case presenting coexistence of pigmented and unpigmented AMs in the same patient and may contribute to further prognostic factor studies in the future research.