title: Incidentally discovered pancreatic intraepithelial neoplasia: what is its clinical significance?
abstract: OBJECTIVE
  Pancreatic intraepithelial neoplasia (PanIN) is a presumed precursor of pancreatic ductal adenocarcinoma (PDAC). We assessed the relationship between incidental PanIN after resection of non-adenocarcinoma lesions and the development of metachronous PDAC in the remnant.
  
  
  METHODS
  We retrospectively reviewed the clinicopathologic data of patients who underwent pancreatectomy for non-PDAC from January 2000 to January 2010. Intraductal papillary mucinous lesions were excluded. All available postoperative imaging and clinical follow-up data were reviewed; the risk of developing PDAC was assessed in patients with a minimum follow-up time of 6 months and with imaging studies available for review.
  
  
  RESULTS
  A total of 584 patients were analyzed. Median age was 59 years (range 10-85 years), and 338 (58 %) were female. The most common lesions for which resection was performed were serous cystic neoplasms (17 %), pancreatic neuroendocrine tumors (38 %), metastatic tumors (9 %), and mucinous cystic neoplasms (7 %). PanIN was identified in 153 (26 %) patients. The majority of these patients had PanIN-1 or -2 (50 and 41 %, respectively), whereas 13 (8 %) had PanIN-3. Of the 506 (87 %) patients with adequate follow-up (median 3.7 years, range 0.5-12.6 years), 1 patient (0.2 %) with PanIN identified at the time of initial resection developed cancer in the remnant. This occurred 4.4 years after a distal pancreatectomy in the setting of PanIN-1B. No patient with PanIN-3 developed cancer during follow-up.
  
  
  CONCLUSIONS
  PanIN was identified in 26 % of patients who underwent resection for histopathology other than PDAC. The presence of PanIN of any grade did not result in an appreciable cancer risk in the pancreatic remnant after short-term follow-up.
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Ioannis T
authors.initials: IT
authors.lastname: Konstantinidis
authors.forename: Eduardo F
authors.initials: EF
authors.lastname: Vinuela
authors.forename: Laura H
authors.initials: LH
authors.lastname: Tang
authors.forename: David S
authors.initials: DS
authors.lastname: Klimstra
authors.forename: Michael I
authors.initials: MI
authors.lastname: D'Angelica
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Dematteo
authors.forename: T Peter
authors.initials: TP
authors.lastname: Kingham
authors.forename: Yuman
authors.initials: Y
authors.lastname: Fong
authors.forename: William R
authors.initials: WR
authors.lastname: Jarnagin
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Allen
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002278:Carcinoma in Situ / Q000473:pathology* / Q000601:surgery; D021441:Carcinoma, Pancreatic Ductal / Q000473:pathology* / Q000601:surgery; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018365:Neoplasm, Residual / Q000473:pathology* / Q000601:surgery; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D012189:Retrospective Studies; D055815:Young Adult