title: MUC2 expression and prevalence of high-grade dysplasia and invasive carcinoma in mixed-type intraductal papillary mucinous neoplasm of the pancreas.
abstract: OBJECTIVE
  Morphological types and mucin protein expressions classify intraductal papillary mucinous neoplasms (IPMNs). Main duct (MD)-IPMN mostly consists of intestinal type (I-type), which expresses MUC2. Branch duct (BD)-IPMN mostly consists of gastric type (G-type), which does not express MUC2. However, the definition of mixed-type IPMN has yet to be clarified and it contains various histological types. The aim of this study was to investigate the relationship between MUC2 expression and the presence of high-grade dysplasia (HGD) and invasive carcinoma, especially in mixed-type IPMN.
  
  
  METHODS
  This retrospective study included 101 consecutive patients with surgically resected IPMNs between April 2001 and October 2012. All patients were morphologically classified into four distinct types (I-type, G-type, PB-type: pancreatobilliary, O-type: oncocytic) and immunohistochemical reactivity of various anti-mucin antibodies were investigated.
  
  
  RESULTS
  According to the classification of the 2012 international guidelines, the numbers (and histomorphological types: I/G/PB/O) of MD, mixed-type, and BD-IPMNs were 16 (12/4/0/0), 45 (16/28/1/0), and 40 (0/38/1/1). Prevalence of MUC2 expression in MD, mixed-type, and BD-IPMNs were 75% (12/16), 36% (16/45), and 0% (0/40). In mixed-type IPMN, the prevalence of HGD and/or invasive carcinoma in MUC2-positive IPMN was significantly higher than that of MUC2-negative IPMN (HGD + invasive carcinoma: 88% vs. 38%, p = 0.0017; invasive carcinoma: 50% vs. 21%, p = 0.042). Multivariate analysis showed that MUC2 expression is an independent predictive factor of HGD and invasive carcinoma in mixed IPMN (odds ratio 14.6, 95% CI 2.5-87.4, p = 0.003).
  
  
  CONCLUSIONS
  In mixed-type IPMN, MUC2 expression clearly identified HGD and invasive carcinoma and may provide most appropriate surgical indication.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Graduate School of Medicine, Kobe University, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Masuda
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Arisaka
authors.forename: Shigeo
authors.initials: S
authors.lastname: Hara
authors.forename: Ippei
authors.initials: I
authors.lastname: Matsumoto
authors.forename: Mamoru
authors.initials: M
authors.lastname: Takenaka
authors.forename: Arata
authors.initials: A
authors.lastname: Sakai
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Shiomi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Matsuki
authors.forename: Maki
authors.initials: M
authors.lastname: Sugimoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Fujita
authors.forename: Takanobu
authors.initials: T
authors.lastname: Hayakumo
authors.forename: Yonson
authors.initials: Y
authors.lastname: Ku
authors.forename: Shuji
authors.initials: S
authors.lastname: Ogino
authors.forename: Takeshi
authors.initials: T
authors.lastname: Azuma
authors.forename: Hiromu
authors.initials: H
authors.lastname: Kutsumi
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D000368:Aged; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D055262:Mucin-2 / Q000096:biosynthesis* / Q000276:immunology; D009077:Mucins / Q000276:immunology; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D010183:Pancreatic Ducts / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D015995:Prevalence; D012189:Retrospective Studies
chemical_list: C524625:MUC2 protein, human; D055262:Mucin-2; D009077:Mucins
keywords: BD-IPMN; CT; ERCP; EUS; EUS-FNA; HGD; High-grade dysplasia; IPMN; Invasive carcinoma; LGD; MCN; MD-IPMN; MPD; MRCP; MRI; MUC2 expression; Mixed-type IPMN; branch duct intraductal papillary mucinous neoplasm; computed tomography; endoscopic retrograde cholangiopancreatography; endoscopic ultrasonography; endoscopic ultrasound-guided fine needle aspiration; high-grade dysplasia; intraductal papillary mucinous neoplasm; low-grade dysplasia; magnetic resonance cholangiopancreatography; magnetic resonance imaging; main duct intraductal papillary mucinous neoplasm; main pancreatic duct; mucinous cystic neoplasm