IgG4-related Sclerosing Disease: Autoimmune Pancreatitis and Extrapancreatic Manifestations

Abstract

Autoimmune pancreatitis is the pancreatic manifestation of IgG4-related sclerosing disease, which recently was recognized as a distinct disease entity. Numerous extrapancreatic organs, such as the bile ducts, gallbladder, kidneys, retroperitoneum, thyroid, salivary glands, lung, mediastinum, lymph nodes, and prostate may be involved, either synchronously or metachronously. Most cases of autoimmune pancreatitis are associated with elevated serum IgG4 levels; extensive IgG4-positive plasma cells; and infiltration of lymphocytes into various organs, which leads to fibrosis. There are several established diagnostic criteria systems that are used to diagnose autoimmune pancreatitis and that rely on a combination of imaging findings of the pancreas and other organs, serologic findings, pancreatic histologic findings, and response to corticosteroid therapy. It is important to recognize multiorgan involvement of IgG4-related sclerosing disease and be familiar with its clinical and imaging features because it demonstrates a favorable response to treatment.

Five Top Stories in Thyroid Pathology

“…87,89,117 As explained earlier, the pathologic features of thyroid involvement are very similar to those of other organs affected in the systemic form of IgG4-RD, 90 especially autoimmune pancreatitis (as more than one-third of affected patients 118 have some form of thyroiditis as well), 90,119 and include diffuse lymphoplasmacytic infiltration, lymphoid follicle formation with germinal centers, dense stromal fibrosis, and follicular cell destruction (Figure 7, A through C). Increased numbers of IgG4-positive plasma cells are usually observed in IgG4-related thyroiditis 109,116 ( Figure 8, A through C).…”

Incidence and outcome of lung involvement in IgG4‐related autoimmune pancreatitis

“…In addition, various types of lung involvement in IgG4-RD, including interstitial pneumonia, inflammatory pseudotumours and lymphadenopathy, have been described. [3][4][5][6][7] In contrast, the clinical characteristics of lung involvement in IgG4-RD, in particular the response to treatment and prognosis, remain unclear. In this study, we retrospectively evaluated the incidence and outcomes of lung involvement in 35 patients with AIP.…”

IgG4 Sclerosing Cholangitis and Post Infantile Giant Cell Hepatitis: A Case Report of an Extraordinary Co-presentation

“…Isolated strictures of the distal common bile duct also are common [21]. Placement of a temporary endoscopic biliary stent or percutaneous biliary drainage was performed in 26 patients (59%) to relieve jaundice [20]. According to the findings of the ERCP; the present case belongs to the group of isolated CBD stricture and placement of a plastic stent was successfully undertaken.…”

“…Valchou et al, in their study of IAC cases, found 43% of cases presenting with isolated extrahepatic bile duct involvement, and only 5% with intrahepatic bile duct involvement, while the copresentation was evident in 52%, and in 20% only the intra-pancreatic portion of the common bile duct was involved [20]. Isolated strictures of the distal common bile duct also are common [21].…”

“…A good initial therapeutic response to corticosteroids is characteristic, particularly in those whose excessive tissue fibrosis has not yet supervened [20]. Without treatment, IgG4-SC may be self-limited, or it may asymptomatically progress and lead to biliary cirrhosis [20].…”