IgG4-related disease in the abdomen: a great mimicker.

IgG4-related disease is a systemic disorder that can involve various abdominal organs. Abdominal manifestations include autoimmune pancreatitis, sclerosing cholangitis, gallbladder pseudotumours, multifocal renal abnormalities, retroperitoneal fibrosis, and sclerosing mesenteritis. Radiological appearances of the IgG4-related disease often resemble malignant tumors and other inflammatory processes, potentially leading to unnecessary invasive procedures. Moreover, a timely diagnosis of IgG4-related disease leads to an effective treatment with steroids. Therefore, it is important to understand the spectrum of imaging manifestations of IgG4-related disease and their differentiating features from other diagnoses.