title: The usefulness of endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of pancreatic neuroendocrine tumors based on the World Health Organization classification.
abstract: BACKGROUND
  We assessed the controversial topic of using 22-gauge needles in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for the diagnosis and evaluation of Ki67 labeling indices (Ki67LI) of pancreatic neuroendocrine tumors (pNET).
  
  
  METHODS
  Thirty-eight patients with pNET who underwent EUS-FNA between January 1, 2008 and December 31, 2012 were enrolled in this study. When available, the Ki67LI and WHO classifications obtained by EUS-FNA and surgical resection were compared.
  
  
  RESULTS
  EUS-FNA with a 22-gauge needle acquired sufficient histological sample to correctly diagnose pNET in 35 cases (92.1%). Both EUS-FNA and surgical histological specimens were available for 19 cases, and grading classes of the 2 procedures were consistent in 17 cases (89.5%) according to the WHO classification based on the Ki67LI. Tumor size was associated with a difference in the Ki67LI between the 2 procedures, although the Ki67LI was almost completely consistent for tumors less than 18 mm in size.
  
  
  CONCLUSIONS
  EUS-FNA with a 22-gauge needle is a safe and highly accurate technique for the diagnosis of pNET. There was a clear correlation between the Ki67LI of histological specimens acquired by EUS-FNA and surgery. EUS-FNA with a 22-gauge needle is useful to predict the WHO classification of pNET.
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine , Sendai , Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Unno
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kanno
authors.forename: Atsushi
authors.initials: A
authors.lastname: Masamune
authors.forename: Atsuko
authors.initials: A
authors.lastname: Kasajima
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Fujishima
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Ishida
authors.forename: Shin
authors.initials: S
authors.lastname: Hamada
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kume
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuta
authors.forename: Morihisa
authors.initials: M
authors.lastname: Hirota
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Motoi
authors.forename: Michiaki
authors.initials: M
authors.lastname: Unno
authors.forename: Tooru
authors.initials: T
authors.lastname: Shimosegawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000379:methods*; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000145:classification / Q000175:diagnosis*; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000145:classification / Q000175:diagnosis*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014944:World Health Organization
keywords: Ki67; endoscopic ultrasonography; endoscopic ultrasound-guided fine needle aspiration; pancreatic neuroendocrine tumors