Case Report
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Sep 26, 2020; 8(18): 4200-4206
Published online Sep 26, 2020. doi: 10.12998/wjcc.v8.i18.4200
Mucinous adenocarcinoma of the buttock associated with hidradenitis: A case report
Sung Jin Kim, Tae Gon Kim, Mi Jin Gu, Sohyun Kim
Sung Jin Kim, Sohyun Kim, Department of Surgery, College of Medicine, Yeungnam University, Daegu 42415, South Korea
Tae Gon Kim, Department of Plastic and Reconstructive Surgery, College of Medicine, Yeungnam University, Daegu 42415, South Korea
Mi Jin Gu, Department of Pathology, College of Medicine, Yeungnam University, Daegu 42415, South Korea
Author contributions: Kim S and Kim SJ were the patient’s surgeons, reviewed the literature and contributed to manuscript drafting; Kim TG performed the reconstruction surgery, reviewed the literature and drafted the manuscript; Gu MJ performed the pathologic test, reviewed the literature and drafted the manuscript; Kim S, Kim SJ, Gu MJ and Kim TG were responsible for the revision of the manuscript for important intellectual content; all authors issued final approval for the version to be submitted.
Informed consent statement: This study was approved by the Institutional Review Board of Yeungnam University Medical Center (approval number: 2020-06-067). The Internal Review Board exempted it from obtaining informed consent from the patients.
Conflict-of-interest statement: The authors declare that they have 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 that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: Sohyun Kim, MD, Assistant Professor, Department of Surgery, College of Medicine, Yeungnam University, 170 Hyeonchung-ro, Nam-gu, Daegu 42415, South Korea. kshgs@yu.ac.kr
Received: July 7, 2020
Peer-review started: July 7, 2020
First decision: July 24, 2020
Revised: August 2, 2020
Accepted: August 26, 2020
Article in press: August 26, 2020
Published online: September 26, 2020
Abstract
BACKGROUND

Mucinous adenocarcinomas of the buttock are rare and have an uncertain etiology and natural course. They are usually related to chronic anal fistulas, hidradenitis suppurativa, or Crohn's disease. Here, we report a case of mucinous adenocarcinoma associated with hidradenitis and contradictory immunochemistry results.

CASE SUMMARY

A 62-year-old man complained of recurrent abscesses of the buttock for 3 years. He had several scars and nodules in bilateral buttocks, with purulent discharge. The skin lesions did not appear to originate from the anus. The patient was diagnosed with recurrent abscesses due to hidradenitis suppurativa at the first visit. He showed purulent and subsequent mucin discharge in the first operation and was diagnosed with mucinous adenocarcinoma. Several examinations were performed to determine disease origin and staging. There were no significant findings or evidence of anal fistulas. Hence, he underwent wide local excision and V-Y advancement flap in the second operation. The final diagnosis was mucinous adenocarcinoma without any evidence of anal fistulas. Additional immunochemistry test results were negative for cytokeratin (CK) 7 and positive for CK20 and CDX2, with a colorectal origin. A pathologist suggested that the disease originated from a chronic anal fistula. The patient has remained free of recurrence for 24 mo.

CONCLUSION

Although the patient with mucinous adenocarcinoma showed an atypical course, immunochemistry helped detect the disease origin.

Keywords: Mucinous adenocarcinoma, Anal fistula, Hidradenitis suppurativa, Wide excision, Immunochemistry test, Case report

Core Tip: In a case of mucinous adenocarcinoma, medical history and examinations suggested hidradenitis suppurativa as the origin. Pathologic results suggested that the disease was related to chronic anal fistulas. Results of the immunochemistry test showed that the disease had a colorectal origin. However, there was no evidence of anal fistulas, and the case did not match the diagnostic criteria previously known. Hence, the authors suggest that this case showed an atypical course related to anal fistulas.