title: Risk of misdiagnosis and overtreatment in patients with main pancreatic duct dilatation and suspected combined/main-duct intraductal papillary mucinous neoplasms.
abstract: BACKGROUND
  Segmental/diffuse dilatation of the main pancreatic duct (MPD) is the typical feature of combined/main-duct intraductal papillary mucinous neoplasms (CMD-IPMNs). MPD dilation in IPMNs may be also expression of mucus hypersecretion/obstructive chronic pancreatitis (OCP). The aim of this study was to evaluate the presence and extension of MPD involvement by tumor/OCP and assess the risk of overtreatment.
  
  
  METHODS
  Retrospective analysis of suspected CMD-IPMNs resected between January 2009 and October 2014 were included. Pathologic correlations among MPD dilatation, IPMN, and OCP was searched.
  
  
  RESULTS
  Overall, 93 patients were resected for suspected CMD-IPMNs. At pathology, CMD-IPMNs were found in 69 patients (74%). Branch-duct IPMNs (BD-IPMNs) were found in 8 cases (9%), pancreatic ductal adenocarcinoma (PDAC) in absence of IPMN in 9 (10%), cystic neuroendocrine tumor (NET G2) in 1 (1%), serous cystadenoma in 2 (2%), and OCP alone/mucinous metaplasia in 4 patients (4%). Overall, 18 patients (19%) underwent an overtreatment because unnecessary (2 BD-IPMNs, 2 serous cystadenomas, and 4 OCPs only) or too extensive resections (9 CMD-IPMNs and 1 PDAC with associated OCP). In these, total pancreatectomy was the most common procedure (67%). Median size of MPD in IPMN-involved area was 12 mm compared with 7 mm when only OCP was found (P < .05).
  
  
  CONCLUSIONS
  There is a considerable risk of overtreatment in patients with a preoperative morphologic diagnosis of CMD-IPMNs. Partial pancreatectomy with margin examination should be performed instead of upfront total pancreatectomy. Radiologic observation can be considered in asymptomatic patients with "worrisome" MPD dilatation (5-9 mm) and lacking other high-risk stigmata.
authors.affiliation: Department of Surgery, Universita' Politecnica delle Marche, Ospedali Riuniti, Ancona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Crippa
authors.affiliation: Department of Surgery, Universita' Politecnica delle Marche, Ospedali Riuniti, Ancona, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Pergolini
authors.affiliation: Department of Biomedical Sciences and Public Health, Universita' Politecnica delle Marche, Ospedali Riuniti, Ancona, Italy.
authors.forename: Corrado
authors.initials: C
authors.lastname: Rubini
authors.affiliation: Division of Pathology, Sacro Cuore-Don Calabria Hospital, Negrar, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Castelli
authors.affiliation: Department of Surgery, Universita' Politecnica delle Marche, Ospedali Riuniti, Ancona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Partelli
authors.affiliation: General Surgery, Sacro Cuore-Don Calabria Hospital, Negrar, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Zardini
authors.affiliation: Department of Biomedical Sciences and Public Health, Universita' Politecnica delle Marche, Ospedali Riuniti, Ancona, Italy.
authors.forename: Giorgia
authors.initials: G
authors.lastname: Marchesini
authors.affiliation: Division of Pathology, Sacro Cuore-Don Calabria Hospital, Negrar, Italy; Department of Pathology, Università di Verona, Verona, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zamboni
authors.affiliation: Department of Surgery, Universita' Politecnica delle Marche, Ospedali Riuniti, Ancona, Italy. Electronic address: falconi.massimo@hsr.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Falconi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis* / Q000601:surgery; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D004108:Dilatation, Pathologic; D005260:Female; D006801:Humans; D008297:Male; D000069342:Medical Overuse / Q000706:statistics & numerical data*; D008875:Middle Aged; D010180:Pancreatectomy / Q000379:methods*; D010183:Pancreatic Ducts / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D050500:Pancreatitis, Chronic / Q000175:diagnosis*; D012189:Retrospective Studies