Immunoglobulin G4-Associated Cholangitis: Two Case Reports and Clinical Use of Classic and Emerging International Diagnostic Criteria.

Immunoglobulin G4-related disease is a multisystem disorder with unique gastrointestinal tract manifestations, often simulating neoplasms and other inflammatory conditions. Appropriate clinical suspicion and application of internationally validated criteria can assist in making the proper diagnosis. This article describes two cases of patients presenting with biliary tract manifestations simulating lymphoproliferative disease and adenocarcinoma, respectively.