Abdominal Manifestations of IgG4-Related Disease

IgG4-related disease is a recently recognized systemic disorder involving multiple organs throughout the body. The multi-organ involvement of this disease was previously thought to occur as isolated, unrelated autoimmune disorders. Although virtually any part of the body may be involved in IgG4-related disease, abdominal manifestations tend to predominate in most affected individuals. While autoimmune pancreatitis is the most commonly encountered abdominal disorder in the setting of IgG4-related disease, the liver, kidneys, gastrointestinal tract, retroperitoneum, and mesentery may likewise be involved. Various diagnostic criteria for IgG4-related disease have been proposed based on physical exam, serology, and histopathologic confirmation. However, imaging plays an essential role in the diagnosis of this disorder, not only to establish the presence of IgG4-related disease, but to assess the severity and extent of systemic disease involvement.