Imaging features of immunoglobulin G4‐related disease

Abstract

SummaryImmunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition that was first recognised as a systemic disease in 2003, when patients with autoimmune pancreatitis were found to have extrapancreatic manifestations. Since 2003, IgG4-RD has been described in a diverse range of other organs including the biliary tree, orbits, lacrimal glands, salivary glands, lungs, kidneys, aorta, retroperitoneum, lymph nodes, pachymeninges, prostate and pituitary gland. The disease frequently occurs in the absence of pancreatic involvement. The imaging manifestations of IgG4-RD are broad and variable depending on the organ involved. The majority of individual organ appearances are non-specific and differentiation between IgG4-RD and potentially more serious conditions is not usually possible based on radiological findings in one organ alone. However, if there are simultaneous findings typical of IgG4-RD in multiple organs then this is a key diagnostic clue and IgG4-RD should be considered as one of the main differentials. This review article examines the spectrum of imaging appearances of IgG4-RD. Increased awareness of the spectrum of radiological appearances of IgG4-RD throughout the body and subsequent consideration of the condition may potentially avoid invasive treatment and lead to more prompt corticosteroid therapy.

Current and future advances in practice: IgG4-related disease

“…Of the patients with IgG4-related pancreatic disease, ≤20% also have biliary involvement manifesting as IgG4-related sclerosing cholangitis or biliary compression from pancreatitis. The most common presentation is painless jaundice, occurring in 70% of patients [ 11–14 ]. Imaging in AIP can present as diffuse or focal involvement (reviewed below).…”

Imaging Features of Toxicities by Immune Checkpoint Inhibitors in Cancer Therapy

“…However, the latter may include focal forms, may show a typical loss of the normal fatty lobulations described as a ‘sausage pancreas’ and may include simultaneous findings in multiple other organs (such as biliary, salivary, aortic and retroperitoneal involvement) [ 26 , 27 ]. Magnetic resonance cholangiopancreatography (MRCP) may show diffused narrow or segmental stenosis of the main pancreatic duct (‘pancreatic duct penetrating sign’) without an upstream dilation, strictures of the pancreatic segment of common bile duct, proximal bile duct dilation and gallbladder enlargement [ 25 , 27 , 28 ]. In addition, immunoglobulin G4-related autoimmune pancreatitis often presents with obstructive jaundice and upper abdominal pain [ 26 ].…”

Autoimmune Pancreatitis

“…On arterial phase images, focal/mass forming AIP is hypovascular, similarly to pancreatic adenocarcinoma [ 12 ]. MRCP or EUS may show the main pancreatic duct penetrating through the mass lesion, suggestive of a positive duct penetrating sign in cases of focal AIP [ 13 , 14 ]. Capsule-like rim may or may not be seen in mass-forming AIP.…”