Difficulty in diagnosing autoimmune pancreatitis by imaging findings

Diagnosis and management of autoimmune pancreatitis: Experience from China

“…The concept of AIP was first proposed by Yoshida et al in 1995 [1] . Hereafter, the concept of AIP has been widely accepted, and its clinical, histologic, radiographic, and serologic features have been characterized [5][6][7][8][9][10][11][12] . The cellular mechanisms and genetic factors contributing to AIP are also investigated [17][18][19] .…”

“…The following characteristics of AIP have been noted [5][6][7][8][9][10][11][12] : (1) predominance of elder male, with mean age of 55-63 years; (2) nonspecific abdominal pain, painless jaundice (> 60%), and, rarely, acute attack of pancreatitis; (3) dense fibrosis with prominent lymphoplasmacytic infiltration in pancreatic lesions; (4) diffuse or focal irregular narrowing of the MPD on ERCP, together with stricture of intrapancreatic common bile duct and dilation of the bile duct upstream; (5) diffuse or focal enlargement of the pancreas; (6) increased ser um γ-globulin or IgG or IG4 levels; (7) the presence of autoantibodies; (8) frequent presence of cholestatic liver dysfunction, hyperbilirubinemia, and elevated CA19-9 level; (9) usually absence of pancreatic calcification and cysts; (10) extrapancreatic organs involvement in autoimmune diseases, such as ulcerative colitis, Sjögren's syndrome, sclerosing cholangitis; and (11) effectiveness of steroid therapy. Sometimes, AIP patients presented with nephrydrosis or upper gastrointestinal bleeding [20] .…”

“…Since Sarles et al first described AIP case in 1961 [4] , increasing numbers of AIP patients have been diagnosed worldwide [5][6][7][8][9] . Although AIP has distinct characteristics at clinical, radiologic, histologic, and serologic findings [1][2][3]8] , due to the extreme similarity in clinical manifestations of pancreaticobiliary malignancies, the benign condition of AIP has frequently been diagnosed or suspected as pancreatic cancer, especially when clinicians have no awareness of AIP, which consequently impose the patients an unnecessary pancreatic resection [10][11][12] . The diagnosis of AIP is mainly based on the diagnostic criteria proposed by the Japan Pancreas Society (JPS) in 2002 [13] .…”

Imaging Appearances of Autoimmune Pancreatitis

“…AIP is mainly indicated by an imaging procedure such as contrast enhanced computed tomography (CT) or magnetic resonance imaging (MRI) (16,(18)(19)(20)(21)(22).…”

The Therapeutic Strategy for Autoimmune Pancreatitis Is Subject to Endoscopic Features of the Duodenal Papilla

“…Type 2 can be misdiagnosed as PSC, and types 3 and 4 are easily mistaken for cholangiocarcinoma. Awareness of this classification could diminish the misdiagnosis of AIP; nevertheless, some cases remain difficult to diagnose [Nakazawa et al 2007], and unnecessary surgery sometimes occurs. The endoscopic differentiation of these two conditions has not yet been fully clarified.…”