Case Report
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Aug 6, 2019; 7(15): 2094-2102
Published online Aug 6, 2019. doi: 10.12998/wjcc.v7.i15.2094
Endometriosis of the duplex appendix: A case report and review of the literature
Ming-Yuan Zhu, Fa-Ming Fei, Jing Chen, Zhong-Cheng Zhou, Bin Wu, Yi-Yu Shen
Ming-Yuan Zhu, Fa-Ming Fei, Jing Chen, Zhong-Cheng Zhou, Bin Wu, Yi-Yu Shen, Department of General Surgery, The Second Affiliated Hospital of Jiaxing University, Jiaxing 314000, Zhejiang Province, China
Author contributions: Zhu MY and Shen YY designed the study; Zhu MY and Fei FM collected the patient’s clinical data; Chen J and Zhou ZC analyzed the data; Zhu MY wrote the manuscript; Wu B revised the manuscript; and all authors read and approved the final manuscript.
Supported by Department of Science and Technology of Jiaxing, No. 2017AY33037.
Informed consent statement: Consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: The authors declare that they have no conflicts 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:
Corresponding author: Yi-Yu Shen, MD, Chief Doctor, Department of General Surgery, The Second Affiliated Hospital of Jiaxing University, 1518 Huancheng North Road, Jiaxing 314000, Zhejiang Province, China.
Telephone: +86-1570-6701708
Received: April 17, 2019
Peer-review started: April 18, 2019
First decision: June 12, 2019
Revised: June 18, 2019
Accepted: June 26, 2019
Article in press: June 26, 2019
Published online: August 6, 2019

Duplication of the appendix is an infrequent congenital malformation with a complex classification. The horseshoe appendix is a subtype of the duplex appendix and is rarely reported in the literature. Endometriosis is a common gynecological disease that rarely occurs in the appendix. Moreover, horseshoe appendix combined with endometriosis has not been previously reported.


Here, we describe a 44-year-old woman who was admitted with a 1-d history of migratory lower right quadrant pain. Physical examination was consistent with the signs of acute appendicitis. The patient underwent an emergency exploratory laparotomy. The distal tip of the appendix was in contact with the cecum by another base, or “horseshoe appendix”. In addition, a small intestinal mass and an ovarian mass were identified. Subsequently, appendectomy, partial resection of the small intestine, and right oophorectomy were successively performed. The histopathology confirmed the diagnosis of acute inflammation of the duplex appendix with endometriosis, small intestine endometriosis, and ovarian endometriosis.


Surgeons need to be aware of the possibility of the duplex appendix when performing an appendectomy, and this study emphasizes the importance of exploring the entire abdomen.

Keywords: Duplex appendix, Horseshoe appendix, Endometriosis, Appendectomy, Case report

Core tip: We describe a patient with endometriosis of the duplex appendix, small intestine, and ovary. There are no similar cases reported. Currently, the diagnosis of duplex appendix and endometriosis is difficult before surgery. Our case suggests that serum carbohydrate antigen 125 levels and fecalith of the appendix may be useful signs for the diagnosis of endometriosis and duplex appendix, respectively. However, the most important procedure is the careful exploration of the abdominal cavity during surgery. Serious legal disputes can occur due to neglecting another infected appendix or not carefully exploring other parts of the abdominal cavity.