Immunoglobulin G4-related Disease and Pancreatic Malignancy: An Association or Two Independent Processes?

Immunoglobulin G4 related disease (IgG4-RD) is a rare multisystem inflammatory disease, in which one of the main gastrointestinal manifestations is autoimmune pancreatitis (AIP) type 1. AIP type 1 is correlated with a clinical presentation of obstructive jaundice, increased serum levels of IgG4 and suggestive pancreatic findings on radiologic imaging. Histo-pathology (HP) and immune-histochemistry (IHC) examinations obtained by biopsy are the gold standard for establishing the diagnosis. Several theories tried to elucidate the correlation between IgG4-RD and pancreatic or other extra-pancreatic malignancies. There are controversial opinions whether AIP type 1 serves as a premalignant state, or whether these two conditions are coexistent. We present a patient who had clinical, laboratory, radiologic and histologic findings that were consistent with a pancreatic space occupying lesion (SOL). As a result, he underwent a Whipple operation, but the IHC findings were compatible with AIP type 1. After 1 year of remission, the patient presented with a new pancreatic SOL that was diagnosed as adenocarcinoma.