title: Diagnostic performance and factors influencing the accuracy of EUS-FNA of pancreatic neuroendocrine neoplasms.
abstract: BACKGROUND
  Multiple studies have investigated sampling adequacy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for pancreatic neuroendocrine neoplasms (pNENs). However, none have described the diagnostic performance of EUS-FNA for pNENs, or the influencing factors. The aim of this study was to evaluate the diagnostic accuracy of EUS-FNA, with post-operative pathological diagnosis as the gold standard, and factors predictive of inadequate EUS sampling.
  
  
  METHODS
  From 1998 to 2014, a total of 698 patients underwent pancreatic resection and 1455 patients underwent EUS-FNA sampling for pancreatic lesions. A total of 410 cases underwent both surgical resection and preceding EUS-FNA. Of these, 60 cases (49 true pNEN, nine non-diagnostic, two misdiagnoses) were included. We studied diagnostic performance of EUS-FNA and factors that were associated with failed diagnosis.
  
  
  RESULTS
  Of the 60 cases, EUS-FNA yield was 49 true-positive cases, two misdiagnoses, and nine non-diagnostic cases (including six suggestive cases). Sensitivity, specificity, and accuracy were 84.5, 99.4, and 97.3 %, respectively; including the six suggestive cases, diagnostic values were 94.8 % sensitivity (55/58), 99.4 % specificity (350/352), and 98.7 % accuracy (405/410). In multivariate analysis, sampling adequacy rates were significantly lower when lesions were located in the pancreatic head [odds ratio (OR) = 10.0] and in tumor-rich stromal fibrosis (OR = 10.45). Tumor size, needle type, tumor grading, presence of cystic component, and time period were not significant factors.
  
  
  CONCLUSIONS
  EUS-FNA offers high accuracy for pNEN. However, location of the tumor in the pancreatic head and presence of rich stromal fibrosis negatively impacts sampling adequacy.
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan. rizasusu@aichi-cc.jp.
authors.forename: Susumu
authors.initials: S
authors.lastname: Hijioka
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hara
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan.
authors.forename: Nobumasa
authors.initials: N
authors.lastname: Mizuno
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imaoka
authors.affiliation: Department of Gastroenterology, Fortis Escorts Liver and Digestive Institute, New Delhi, India.
authors.forename: Vikram
authors.initials: V
authors.lastname: Bhatia
authors.affiliation: Department of Tropical Medicine and Gastroenterology, Assiut University Hospital, Assiut, Egypt.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Mekky
authors.affiliation: Innovative Clinical Research Center, Kanazawa University, Kanazawa, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yoshimura
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Okuno
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hieda
authors.affiliation: Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tajika
authors.affiliation: Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ishihara
authors.affiliation: Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yatabe
authors.affiliation: Department of Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimizu
authors.affiliation: Department of Endoscopy, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Niwa
authors.affiliation: Department of Gastroenterology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamao
mesh_terms: D000328:Adult; D000368:Aged; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Diagnosability; EUS-FNA; Pancreatic neuroendocrine neoplasms