Autoimmune pancreatitis: The Last Puzzle Piece of IgG4-Related Disease

Immunoglobulin G4-related systemic disorder (IgG4-RD) is an under-diagnosed fibro-inflammatory disorder with unknown etiology and multiorgan involvement. IgG4-RD manifestations consist of lymphadenopathy, extrapancreatic bile duct lesions, lacrimal and salivary gland lesions, hypothyroidism, retroperitoneal fibrosis, and kidney mass. We report the case of a 46-yearold patient, with moderate persistent asthma and chronic hyperplastic rhinosinusitis, who presented at emergency department because of obstructive jaundice due to a mass in the pancreatic head. The pathology of the surgical specimen disclosed lymphoplasmacytic inflammation with fibrosis of intra and inter-lobular septs and ducts ectasia and abundant infiltration of plasmacytes, most of whom being IgG4-positive (> 200/hpf). These findings were consistent with the diagnosis of IgG4-RD. The patient’s medical history suggests pancreatitis is the last piece of the jigsaw puzzle that initiated years before with swelling of submandibular glands and and enlarged lacrimal glands.