IgG4-related Sclerosing Disease of the Gallbladder: Incidental Malignancy Mimicker Associated With Cholelithiasis?

Abstract

T he family of immunoglobulin G4-related disease (IgG4-RD) is a multisystem chronic fibroinflammatory condition affecting various organ systems with a tendency to develop tumor-like masses, which may result in biopsies due to the concern for malignancy. The gastrointestinal tract (GIT), specifically the pancreaticobiliary tree, the salivary gland, the lung, the kidney, the retroperitoneum, and the meninges are the most common sites of the disease. [1][2][3] Studies have shown that the chronicity of the disease, its responsiveness to treatment with steroids, and its association with autoantibodies all support an immune-mediated etiology. However, the pathogenesis of IgG4-RD remains incompletely understood. 4,5 Although IgG4-related cholecystitis has been described in case reports, it is rarely encountered by pathologists. As a result, its diagnosis is sometimes problematic, and the findings are frequently misinterpreted as other conditions, including xanthogranulomatous cholecystitis (XGC), primary sclerosing cholangitis (PSC), or gallbladder malignancies including lymphoma and bile duct carcinoma. 6 Herein, we provide information regarding the clinical, radiological, and pathological findings in IgG4-RD involving the gallbladder. We also include a description of the findings in 7 cases of IgG4-related cholecystitis, including patient demographics, histomorphology, and differential diagnosis.