Autoimmune pancreatitis - the story so far

Full text: Learning objectives: to learn about the main imaging diagnostic findings of AIP and the International Consensus Diagnostic Criteria (ICDC); to understand the best strategies for distinguishing AIP from pancreatic cancer; to emphasise the central role of radiology in the era of "clinical decision making" Autoimmune Pancreatitis (AIP) was first described in 1961 and represents a rare form of immune mediated chronic pancreatitis which is characterised by a marked infiltration of lymphocytes and plasma cells into pancreatic tissue. Whilst the majority of cases present with diffuse gland involvement, approximately 30% of patient's demonstrate either segmental or focal involvement of the pancreas. Clinical presentation is very variable with patients describing a range of symptoms. Imaging plays a central role in the diagnosis and management of AIP and knowledge of the radiological appearances, which can vary significantly due to the various degrees of fibrosis and inflammatory infiltrate, is critical. Cardinal features include focal or diffuse pancreatic enlargement with the loss of normal lobular architecture. Post contrast enhancement features of the pancreas may also be useful. In addition, pancreatic duct involvement as demonstrated by single or multiple focal strictures with limited more proximal dilatation is common as well as infiltration of the common bile duct.Whilst multimodality appearances may suggest a diagnosis of AIP correlation with clinical history, serology and histopathology is mandatory in order to accurately diagnose atypical cases