Wang KR, Sha SM, Wang SH, Zhao P, Shi HT, Liu L, Wu J, Zhao G. Biliary stricture as an atypical presentation of type 2 autoimmune pancreatitis: A case report. World J Gastroenterol 2026; 32(16): 117109 [DOI: 10.3748/wjg.v32.i16.117109]
Corresponding Author of This Article
Gang Zhao, MD, Department of Gastroenterology, The Second Affiliated Hospital of Xi’an Jiaotong University, No. 157 Xiwu Road, Xi’an 710004, Shaanxi Province, China. zhaogang799@mail.xjtu.edu.cn
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Gastroenterology & Hepatology
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Case Report
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Apr 28, 2026 (publication date) through Apr 17, 2026
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World Journal of Gastroenterology
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1007-9327
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Baishideng Publishing Group Inc, 7041 Koll Center Parkway, Suite 160, Pleasanton, CA 94566, USA
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Wang KR, Sha SM, Wang SH, Zhao P, Shi HT, Liu L, Wu J, Zhao G. Biliary stricture as an atypical presentation of type 2 autoimmune pancreatitis: A case report. World J Gastroenterol 2026; 32(16): 117109 [DOI: 10.3748/wjg.v32.i16.117109]
World J Gastroenterol. Apr 28, 2026; 32(16): 117109 Published online Apr 28, 2026. doi: 10.3748/wjg.v32.i16.117109
Biliary stricture as an atypical presentation of type 2 autoimmune pancreatitis: A case report
Kai-Ruo Wang, Su-Mei Sha, Shen-Hao Wang, Ping Zhao, Hai-Tao Shi, Le Liu, Jie Wu, Gang Zhao
Kai-Ruo Wang, Su-Mei Sha, Shen-Hao Wang, Ping Zhao, Hai-Tao Shi, Gang Zhao, Department of Gastroenterology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
Le Liu, Department of Medical Imaging, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
Jie Wu, Department of Pathology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, Shaanxi Province, China
Co-first authors: Kai-Ruo Wang and Su-Mei Sha.
Author contributions: Wang KR was responsible for conceptualization, investigation, data curation, funding acquisition, writing original draft; Sha SM was responsible for conceptualization, writing review and editing, supervision; Wang KR and Sha SM contributed equally as co-first authors; Wang SH was responsible for methodology; Zhao P was responsible for data curation; Shi HT was responsible for supervision; Liu L was responsible for methodology; Wu J was responsible for validation; Zhao G was responsible for conceptualization and resources; all of the authors read and approved the final version of the manuscript to be published.
Supported by National Natural Science Foundation of China, No. 82400642.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: All authors declare no conflict of interest in publishing the manuscript.
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).
Corresponding author: Gang Zhao, MD, Department of Gastroenterology, The Second Affiliated Hospital of Xi’an Jiaotong University, No. 157 Xiwu Road, Xi’an 710004, Shaanxi Province, China. zhaogang799@mail.xjtu.edu.cn
Received: December 4, 2025 Revised: January 27, 2026 Accepted: March 9, 2026 Published online: April 28, 2026 Processing time: 134 Days and 10.3 Hours
Abstract
BACKGROUND
Type 2 autoimmune pancreatitis (AIP-2) is a rare immunoglobulin G4 (IgG4)-negative inflammatory disease whose diagnosis is often challenging because it closely mimics pancreaticobiliary malignancies, frequently resulting in misdiagnosis and unnecessary surgery.
CASE SUMMARY
A 35-year-old man presented with obstructive jaundice. Imaging revealed pancreatic enlargement and a distal common bile duct stricture, whereas serum IgG4 levels were normal. Given the strong suspicion of malignancy, he underwent pancreaticoduodenectomy. Histopathological examination of the resected specimen revealed a fibrotic process with granulocytic epithelial lesions and rare IgG4-positive cells, confirming AIP-2. The thickened common bile duct wall was interpreted as a secondary change resulting from pancreatic inflammation.
CONCLUSION
AIP-2 must be considered in IgG4-negative obstructive jaundice with biliary stricture.
Core Tip: Type 2 autoimmune pancreatitis is an immunoglobulin G4-negative inflammatory disorder typically confined to the pancreas. In the present case, thickening of the common bile duct wall was observed, which may represent secondary changes resulting from extrinsic compression due to pancreatic inflammation. Mimicking pancreaticobiliary malignancies, type 2 autoimmune pancreatitis should be included in the differential diagnosis of obstructive jaundice to prevent unwarranted surgical intervention.
