Navigating the Challenges Associated With a Diagnosis of Autoimmune Pancreatitis and IgG4-Related Sclerosing Cholangitis.

CONTEXT.—: 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, including 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.

OBJECTIVE.—: 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.

CONCLUSIONS.—: 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.