title: Usefulness of EUS combined with contrast-enhancement in the differential diagnosis of malignant versus benign and preoperative localization of pancreatic endocrine tumors.
abstract: BACKGROUND
  Pancreatic endocrine tumors (PETs) develop in relatively few patients, but they are often difficult to diagnose because of their small size and various clinical symptoms.
  
  
  OBJECTIVE
  The aim of this study was to investigate the usefulness of EUS combined with contrast enhancement (CE-EUS) in the preoperative localization of PETs and the differentiation between malignant and benign PETs.
  
  
  METHODS
  Single-center retrospective study.
  
  
  METHODS
  Sixty-two pathologically certified PETs of 41 patients who underwent EUS, multiphasic multidetector computed tomography (MDCT), and transabdominal US at our institute since 2001.
  
  
  METHODS
  Intravenous injection of US contrast media.
  
  
  METHODS
  Comparison of EUS, MDCT, and US in the preoperative identification of PETs, and the characteristic findings of EUS with malignancy.
  
  
  RESULTS
  EUS showed high sensitivity (95.1%) in identifying PETs compared with MDCT (80.6%) and US (45.2%). Multivariable logistic regression analysis showed that heterogeneous ultrasonographic texture was the most significant factor for malignancy (OR = 53.33; 95% CI, 10.79-263.58). Most heterogeneous hypoechoic areas and anechoic areas corresponded to hemorrhage or necrosis on pathologic examination. They were identified as filling defects in CE-EUS and were more clearly recognized than in conventional EUS.
  
  
  CONCLUSIONS
  Retrospective study.
  
  
  CONCLUSIONS
  EUS has higher sensitivity in preoperative localization of PETs compared with MDCT and US. The characteristics of EUS and CE-EUS findings in malignant PETs were clarified, and they will improve the diagnostic accuracy of PETs.
authors.affiliation: Department of Gastroenterology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Akihiro
authors.initials: A
authors.lastname: Itoh
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kawashima
authors.forename: Eizaburo
authors.initials: E
authors.lastname: Ohno
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsubara
authors.forename: Yuya
authors.initials: Y
authors.lastname: Itoh
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Masanao
authors.initials: M
authors.lastname: Nakamura
authors.forename: Ryoji
authors.initials: R
authors.lastname: Miyahara
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hayashi
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ishigami
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Katano
authors.forename: Naoki
authors.initials: N
authors.lastname: Ohmiya
authors.forename: Hidemi
authors.initials: H
authors.lastname: Goto
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hirooka
mesh_terms: D007516:Adenoma, Islet Cell / Q000000981:diagnostic imaging / Q000473:pathology; D000328:Adult; D000368:Aged; D018273:Carcinoma, Islet Cell / Q000000981:diagnostic imaging / Q000473:pathology; D003287:Contrast Media; D003937:Diagnosis, Differential; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging / Q000473:pathology; D010179:Pancreas / Q000000981:diagnostic imaging* / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D003287:Contrast Media