Case Report
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Oct 16, 2021; 9(29): 8773-8781
Published online Oct 16, 2021. doi: 10.12998/wjcc.v9.i29.8773
Isolated mass-forming IgG4-related sclerosing cholangitis masquerading as extrahepatic cholangiocarcinoma: A case report
Sanghyun Song, Sungho Jo
Sanghyun Song, Sungho Jo, Department of Surgery, Dankook University Hospital, Cheonan 31116, Chungnam Province, South Korea
Author contributions: Song S participated in the operation, reviewed the literature, and drafted the manuscript; Jo S performed the operation, designed the report, and was responsible for the revision of the manuscript for important intellectual content; all authors were involved in managing the case and editing the manuscript, and issued final approval for the version to be submitted.
Informed consent statement: Written informed 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 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: Sungho Jo, MD, PhD, Professor, Department of Surgery, Dankook University Hospital, 201 Manghyang-ro, Dongnam-gu, Cheonan 31116, Chungnam Province, South Korea. agapejsh@dankook.ac.kr
Received: June 26, 2021
Peer-review started: June 26, 2021
First decision: July 16, 2021
Revised: July 20, 2021
Accepted: July 29, 2021
Article in press: July 29, 2021
Published online: October 16, 2021
Abstract
BACKGROUND

IgG4-related sclerosing cholangitis (IgG4-RSC) is an uncommon benign disease, and its rarer, isolated and mass-forming subtype poses a significant challenge to differential diagnosis from cholangiocarcinoma of the extrahepatic bile duct. We herein report a case of isolated IgG4-RSC with an obstructing bile duct mass, for which extrahepatic bile duct resection was performed under the impression of proximal common bile duct (CBD) cancer.

CASE SUMMARY

A 79-year-old male was admitted for jaundice that had developed 1 mo prior. There was no family history for autoimmune diseases or biliary cancer. Computed tomography (CT) and magnetic resonance cholangiopancreaticography revealed a short segmental concentric wall thickening of the proximal CBD with diffuse dilatation of the bile duct to the periphery. The endoscopic biopsy specimen showed no malignant cells. Positron emission tomography-CT showed a focal hypermetabolic lesion (SUVmax 4.2) in and around the proximal CBD area. With the impression of proximal CBD cancer, we performed segmental resection of the extrahepatic bile duct. Histopathology demonstrated marked sclerosis with diffuse lymphoplasmacytic infiltration and some eosinophils. Immunohistochemical staining for IgG4 showed increased positivity in some areas (up to 30/high-power field) and IgG4+/IgG+ cell ratio as 30%-50%. Pathologists’ impression was IgG4-related sclerosing disease. Follow-up serum IgG4 levels were continuously elevated; however, no evidence of relapse or other organ involvement related to IgG4-RSC presented.

CONCLUSION

Isolated and mass-forming IgG4-RSC displays striking similarity with cholangiocarcinoma. To avoid unnecessary major surgery, high index of suspicion is needed.

Keywords: Immunoglobulin G, Sclerosis, Cholangitis, Cholangiocarcinoma, Differential diagnosis, Case report

Core Tip: IgG4-related sclerosing cholangitis (IgG4-RSC) is an emerging disease and shows frequent other-organ involvement, including of the pancreas. However, when isolation without pancreatic involvement and biliary mass formation are combined, IgG4-RSC becomes extremely rare and brings about a striking confusion in differentiation from cholangiocarcinoma. Avoiding unnecessary surgery and providing proper treatment in patients with isolated and mass-forming IgG4-RSC could be achieved through high index of suspicion according to the amount of information on the five cardinal features (histology, imaging, serology, other-organ involvement, and response to steroid therapy).