IgG4-Related Pancreato-Biliary Disease in the Disguise of Malignancy.

The Immunoglobulin G4-related disease (IgG4-RD) is a multisystem inflammatory condition. Pancreaticobiliary manifestations often present as mass lesions that mimic malignancies. The diagnosis is confirmed by histopathological examination, that shows lymphoplasmacytic infiltration, storiform fibrosis, obliterative phlebitis, and positive immunohistochemistry for IgG4. We encountered 3 such patients in a tertiary care hospital in India. Two patients presented with obstructive jaundice and the third with pain abdomen. They had resectable lesions involving the pancreatic head, the right hepatic duct, and gallbladder fundus, respectively, on imaging. Tumor markers were not significantly elevated in any of them. All 3 patients underwent radical surgeries, suspecting malignancy. Surgical specimens showed typical features of IgG4-RD on histomorphology. Serum IgG4 level was elevated in first 2 patients but was normal in sclerosing cholecystitis patient. To conclude, IgG4-RD is a malignant mimicker; hence, on clinical suspicion, liberal attempts for tissue diagnosis may avoid radical surgeries.