Isolated Immunoglobulin G4-related sclerosing cholecystitis mimicking gall bladder cancer: A case report and review of literature

Immunoglobulin G4-related sclerosing cholecystitis (IgG4-CC) is a localised manifestation of a systemic disorder termed IgG4-related disease (IgG4-RD). Here, we report a rare case of isolated IgG4-CC presented with anorexia, weight loss and pain in the right hypochondrium. Abdominal ultrasonography showed diffuse thickening of the gall bladder, which was difficult to distinguish from cancer. Serum IgG4 level was elevated. As initial symptoms and imaging pointed towards malignancy, a laparoscopic cholecystectomy was done to rule out malignancy. Histopathology showed the classic triad of dense transmural lymphoplasmacytic inflammation, prominent storiform fibrosis and obliterative phlebitis. A definite diagnosis of IgG4-CC was established using the 2020 revised comprehensive diagnostic criteria for IgG4-RD. As per this criterion, a combination of clinico-radiologic (thickened gall bladder), serologic (elevated IgG4 level) and two of the three pathologic findings (lymphoplasmacytic infiltration and typical storiform fibrosis/obliterative phlebitis) helped in making an accurate diagnosis. After steroid therapy, the patient went into remission. Awareness of the disease and clinicopathologic correlation could help in early diagnosis and management.