The pancreatobiliary tract exhibits a spectrum of heterogeneous fibroinflammatory conditions that may be the result of a primary immune-mediated mechanism, or a reaction to neoplasm. This often results in significant overlap regarding clinical presentation, symptoms, radiographic findings, serology, and histopathology between inflammatory and neoplastic lesions of the pancreas, which can lead to inadvertent surgical intervention. Among the multitude of primary fibroinflammatory pancreatic diseases, autoimmune pancreatitis, to include type 1 and type 2 autoimmune pancreatitis, and immunoglobulin G4–related sclerosing cholangitis (IgG4-RSC) are particularly challenging and require a multidisciplinary perspective to reliably make a diagnosis. This is of particular significance because these diseases typically have a favorable prognosis and readily respond to steroid therapy.


To present a multimodal approach to highlight distinctive and overlapping qualities that will aid in the diagnosis of these entities.

Data Sources.—

The review and analysis of literature describing autoimmune pancreatitis types 1 and 2 and IgG4-RSC.


Diagnosis of autoimmune pancreatitis types 1 and 2, and IgG4-RSC requires a multimodal approach that relies on clinical, radiographic, serologic, histopathologic, and immunohistochemical correlation.

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Author notes

The authors have no relevant financial interest in the products or companies described in this article.

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Presented in part at the Companion Meeting of the Pancreatobiliary Pathology Society at the virtual 2021 United States and Canadian Academy of Pathology Annual Meeting; March 13–18, 2021.

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