title: Nonneoplastic mimickers of pancreatic neoplasms.
abstract: BACKGROUND
  A variety of nonneoplastic conditions may form pancreatic masses that mimic carcinoma. Approximately 5% to 10% of pancreatectomies performed with the clinical diagnosis of pancreatic cancer prove on microscopic evaluation to be pseudotumors.
  
  
  OBJECTIVE
  To illustrate the clinical and pathologic characteristics of the 2 most frequent pseudotumoral inflammatory conditions, autoimmune pancreatitis and paraduodenal pancreatitis, and describe the criteria that may be useful in the differential diagnosis versus pancreatic carcinoma.
  
  
  METHODS
  Recent literature and the authors' experience with the clinical and pathologic characteristics of autoimmune pancreatitis and paraduodenal pancreatitis.
  
  
  CONCLUSIONS
  The knowledge of the clinical, radiologic, and pathologic findings in both autoimmune pancreatitis and paraduodenal pancreatitis is crucial in making the correct preoperative diagnosis. Autoimmune pancreatitis, which occurs in isolated or syndromic forms, is characterized by a distinctive fibroinflammatory process that can either be limited to the pancreas or extend to the biliary tree. Its correct preoperative identification on biopsy material with ancillary immunohistochemical detection of dense immunoglobulin G4-positive plasma cell infiltration is possible and crucial to prevent major surgery and to treat these patients with steroid therapy. Paraduodenal pancreatitis is a special form of chronic pancreatitis that affects young males with a history of alcohol abuse and predominantly involves the duodenal wall in the region of the minor papilla. Pathogenetically, the anatomical and/or functional obstruction of the papilla minor, resulting from an incomplete involution of the intraduodenal dorsal pancreas, associated with alcohol abuse represents the key factor. Endoscopic drainage of the papilla minor, with decompression of the intraduodenal and dorsal pancreas, might be considered in these patients.
authors.affiliation: Department of Pathology, University of Verona, Ospedale Sacro Cuore-Don Calabria, Via don Sempreboni 5, 37024 Negrar-Verona, Italy. giuseppe.zamboni@sacrocuore.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zamboni
authors.forename: Paola
authors.initials: P
authors.lastname: Capelli
authors.forename: Aldo
authors.initials: A
authors.lastname: Scarpa
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bogina
authors.forename: Anna
authors.initials: A
authors.lastname: Pesci
authors.forename: Eleonora
authors.initials: E
authors.lastname: Brunello
authors.forename: Günter
authors.initials: G
authors.lastname: Klöppel
mesh_terms: D003937:Diagnosis, Differential; D006104:Granuloma, Plasma Cell / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D010195:Pancreatitis / Q000175:diagnosis / Q000473:pathology