title: Characterization of epithelial subtypes of intraductal papillary mucinous neoplasm of the pancreas with endoscopic ultrasound and cyst fluid analysis.
abstract: OBJECTIVE
  Intraductal papillary mucinous neoplasm (IPMN) consists of four epithelial subtypes. There are limited data on the endoscopic ultrasound (EUS) findings and/or cyst fluid analysis of the epithelial subtypes. The objective of this study was to determine whether there are differences in EUS and cyst fluid characteristics (carcinoembryonic antigen [CEA] concentration and cytology) among the subtypes.
  
  
  METHODS
  The study cohort consisted of 85 patients (median age 68 years, 40 men) with resected and histologically confirmed branch-duct or mixed-type IPMNs who underwent preoperative EUS-guided fine-needle aspiration between 1999 and 2010 for the evaluation of pancreatic cysts. EUS and cyst fluid characteristics were analyzed retrospectively and correlated with the subtypes.
  
  
  RESULTS
  The numbers of evaluated cystic lesions were 1 in 79 patients, 2 in 5 patients, and 3 in 1 patient. Of 92 IPMNs analyzed, gastric-type IPMNs were the most common (n = 68, 73.9 %), followed by intestinal (n = 17, 18.5 %), oncocytic (n = 5, 5.4 %), and pancreatobiliary subtypes (n = 2, 2.2 %). Gastric-type IPMNs were significantly smaller (cutoff 30 mm; P = 0.002), and less likely than other subtypes to have a mass lesion or mural nodule (P = 0.046) on EUS. Cyst fluid CEA concentration varied among the subtypes (median concentrations for gastric, intestinal, oncocytic, and pancreatobiliary types 619.8, 83.0, 5.1, and 270.0 ng/mL, respectively; P = 0.012). The presence of neoplastic epithelial cells (P = 0.624) and extracellular mucin (P = 0.208) on cytology had no association with subtypes.
  
  
  CONCLUSIONS
  Gastric-type IPMNs, the most common subtype, are characterized by high concentrations of cyst fluid CEA, small cyst diameter, and low risk EUS imaging features.
authors.affiliation: Gastrointestinal Unit, Massachusetts General Hospital, Boston, Massachusetts, United States.
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Yoon
authors.affiliation: Gastrointestinal Unit, Massachusetts General Hospital, Boston, Massachusetts, United States.
authors.forename: Ebubekir S
authors.initials: ES
authors.lastname: Daglilar
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, United States.
authors.forename: Mari
authors.initials: M
authors.lastname: Mino-Kenudson
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, United States.
authors.forename: Vicente
authors.initials: V
authors.lastname: Morales-Oyarvide
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, United States.
authors.forename: Martha B
authors.initials: MB
authors.lastname: Pitman
authors.affiliation: Gastrointestinal Unit, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, United States.
authors.forename: William R
authors.initials: WR
authors.lastname: Brugge
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis*; D000231:Adenocarcinoma, Papillary / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D015203:Reproducibility of Results; D012189:Retrospective Studies