title: Contrast-enhanced endoscopic ultrasonography can predict a higher malignant potential of gastrointestinal stromal tumors by visualizing large newly formed vessels.
abstract: BACKGROUND
  The aim of this study was to elucidate the histologic and clinical implications of detection of intratumoral vessels on contrast-enhanced endoscopic ultrasonography (CE-EUS) in gastrointestinal stromal tumors (GISTs).
  
  
  METHODS
  Thirteen patients with a GIST, all of whom were referred for surgery, underwent presurgical CE-EUS. The malignant potential, assessed according to the modified Fletcher risk classification system, and the histologic degree of angiogenesis were compared with the presence or absence of intratumoral vessels on CE-EUS.
  
  
  RESULTS
  Of the six tumors with intratumoral vessels observed on CE-EUS, five were intermediate- or high-risk GISTs, and the remaining seven negative cases were categorized as very low risk or low risk. The presence of intratumoral vessels on CE-EUS was significantly correlated with a higher-risk classification (p = 0.005). On histologic examination, all GISTs having visualized vessels incorporated vessels of more than 500 μm in diameter. The large intratumoral vessels of the five intermediate- or high-risk GISTs lacked elastic fibers, suggesting that they were neovascular in nature. These higher-risk tumors were also found, by immunohistochemical analysis, to have high expression of vascular endothelial growth factor.
  
  
  CONCLUSIONS
  Intratumoral vessels observed in GISTs on CE-EUS are correlated with a higher degree of angiogenesis, resulting in higher malignant potential.
authors.affiliation: Second Department of Internal Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama City, Wakayama, 641-0012, Japan.
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Jun
authors.initials: J
authors.lastname: Kato
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ueda
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Hiroko
authors.initials: H
authors.lastname: Abe
authors.forename: Takashi
authors.initials: T
authors.lastname: Tamura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Itonaga
authors.forename: Takeichi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Hiroki
authors.initials: H
authors.lastname: Maeda
authors.forename: Kosaku
authors.initials: K
authors.lastname: Moribata
authors.forename: Toru
authors.initials: T
authors.lastname: Niwa
authors.forename: Takao
authors.initials: T
authors.lastname: Maekita
authors.forename: Mikitaka
authors.initials: M
authors.lastname: Iguchi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tamai
authors.forename: Masao
authors.initials: M
authors.lastname: Ichinose
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D004386:Duodenum / Q000098:blood supply / Q000000981:diagnostic imaging; D016099:Endoscopy, Gastrointestinal; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging*; D046152:Gastrointestinal Stromal Tumors / Q000098:blood supply* / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging*; D013270:Stomach / Q000098:blood supply / Q000000981:diagnostic imaging; D014463:Ultrasonography
chemical_list: D003287:Contrast Media
keywords: GIST; angiogenesis; contrast-enhanced endoscopic ultrasonography; risk classification