title: Autoimmune pancreatitis: Multimodality non-invasive imaging diagnosis.
abstract: Autoimmune pancreatitis (AIP) is characterized by obstructive jaundice, a dramatic clinical response to steroids and pathologically by a lymphoplasmacytic infiltrate, with or without a pancreatic mass. Type 1 AIP is the pancreatic manifestation of an IgG4-related systemic disease and is characterized by elevated IgG4 serum levels, infiltration of IgG4-positive plasma cells and extrapancreatic lesions. Type 2 AIP usually has none or very few IgG4-positive plasma cells, no serum IgG4 elevation and appears to be a pancreas-specific disorder without extrapancreatic involvement. AIP is diagnosed in approximately 2%-6% of patients that undergo pancreatic resection for suspected pancreatic cancer. There are three patterns of autoimmune pancreatitis: diffuse disease is the most common type, with a diffuse, "sausage-like" pancreatic enlargement with sharp margins and loss of the lobular contours; focal disease is less common and manifests as a focal mass, often within the pancreatic head, mimicking a pancreatic malignancy. Multifocal involvement can also occur. In this paper we describe the features of AIP at ultrasonography, computed tomography, magnetic resonance and positron emission tomography/computed tomography imaging, focusing on diagnosis and differential diagnosis with pancreatic ductal adenocarcinoma. It is of utmost importance to make an early correct differential diagnosis between these two diseases in order to identify the optimal therapeutic strategy and to avoid unnecessary laparotomy or pancreatic resection in AIP patients. Non-invasive imaging plays also an important role in therapy monitoring, in follow-up and in early identification of disease recurrence.
authors.affiliation: Stefano Crosara, Mirko D'Onofrio, Riccardo De Robertis, Emanuele Demozzi, Stefano Canestrini, Giulia Zamboni, Roberto Pozzi Mucelli, Department of Radiology, University Hospital GB Rossi, University of Verona, 37134 Verona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Crosara
authors.affiliation: Stefano Crosara, Mirko D'Onofrio, Riccardo De Robertis, Emanuele Demozzi, Stefano Canestrini, Giulia Zamboni, Roberto Pozzi Mucelli, Department of Radiology, University Hospital GB Rossi, University of Verona, 37134 Verona, Italy.
authors.forename: Mirko
authors.initials: M
authors.lastname: D'Onofrio
authors.affiliation: Stefano Crosara, Mirko D'Onofrio, Riccardo De Robertis, Emanuele Demozzi, Stefano Canestrini, Giulia Zamboni, Roberto Pozzi Mucelli, Department of Radiology, University Hospital GB Rossi, University of Verona, 37134 Verona, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: De Robertis
authors.affiliation: Stefano Crosara, Mirko D'Onofrio, Riccardo De Robertis, Emanuele Demozzi, Stefano Canestrini, Giulia Zamboni, Roberto Pozzi Mucelli, Department of Radiology, University Hospital GB Rossi, University of Verona, 37134 Verona, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Demozzi
authors.affiliation: Stefano Crosara, Mirko D'Onofrio, Riccardo De Robertis, Emanuele Demozzi, Stefano Canestrini, Giulia Zamboni, Roberto Pozzi Mucelli, Department of Radiology, University Hospital GB Rossi, University of Verona, 37134 Verona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Canestrini
authors.affiliation: Stefano Crosara, Mirko D'Onofrio, Riccardo De Robertis, Emanuele Demozzi, Stefano Canestrini, Giulia Zamboni, Roberto Pozzi Mucelli, Department of Radiology, University Hospital GB Rossi, University of Verona, 37134 Verona, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Zamboni
authors.affiliation: Stefano Crosara, Mirko D'Onofrio, Riccardo De Robertis, Emanuele Demozzi, Stefano Canestrini, Giulia Zamboni, Roberto Pozzi Mucelli, Department of Radiology, University Hospital GB Rossi, University of Verona, 37134 Verona, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pozzi Mucelli
mesh_terms: D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology / Q000628:therapy; D049448:Cholangiopancreatography, Magnetic Resonance; D003937:Diagnosis, Differential; D006801:Humans; D064847:Multimodal Imaging / Q000379:methods*; D010195:Pancreatitis / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology / Q000628:therapy; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D014057:Tomography, X-Ray Computed; D018615:Ultrasonography, Doppler, Color
keywords: Autoimmune pancreatitis; Computed tomography; Magnetic resonance; Pancreatic imaging; Ultrasonography