Dr. Diego Salinas Rodríguez, Dr. Guillermo Elizondo Riojas

Department of Radiology and Imaging, Hospital Universitario "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León, Monterrey, México.

Corresponding Author: Dr. Diego Salinas Rodríguez, Department of Radiology and Imaging, Hospital Universitario "Dr. José Eleuterio González" Universidad Autónoma de Nuevo León, Monterrey, México.

Citation: Dr. Diego Salinas Rodríguez, Dr. Guillermo Elizondo Riojas (2025). Type 1 Autoimmune Pancreatitis Mimicking Pancreatic Malignancy: A Clinical Case. American J Case Rep Clin Imag. 2025; September, 2(2),1-4.

Copyrights © 2025, Diego Salinas Rodríguez. This article is licensed under the Creative Commons Attribution-Non-Commercial-4.0-International-License-(CCBY-NC) (https://amejcaserepclinimag.com/blogpage/copyright-policy). Usage and distribution for commercial purposes require written permission.

Abstract:

Autoimmune pancreatitis is a rare form of chronic pancreatitis that can mimic pancreatic malignancy. We report the case of a 55-year-old male presenting with obstructive jaundice and abdominal discomfort. Imaging studies, including ultrasonography and contrast-enhanced computed tomography, revealed a prominent pseudomass in the pancreatic head. However, a narrowed pancreatic duct and diffusely enlarged pancreas were observed, which contrast with typical findings of malignancy. Additionally, the pancreas exhibited a capsule-like rim and delayed contrast enhancement. Notably, extrapancreatic findings, such as biliary ductal thickening, peripancreatic lymphadenopathy, and retroperitoneal fibrosis, were pivotal in steering the diagnosis toward type 1 autoimmune pancreatitis. The diagnosis was made based on the constellation of imaging findings, the favorable clinical response to corticosteroid therapy, and elevated serum IgG4 levels. This case highlights the importance of recognizing both pancreatic and extrapancreatic manifestations of autoimmune pancreatitis to facilitate early and accurate diagnosis.

Keywords: Autoimmune Pancreatitis, Pancreatic Pseudotumor, IgG4-related Disease.