title: Efficacy of endoscopic ultrasonography and endoscopic ultrasonography-guided fine-needle aspiration for the diagnosis and grading of pancreatic neuroendocrine tumors.
abstract: OBJECTIVE
  Pancreatic neuroendocrine tumors (pNETs) are histologically categorized according to the WHO 2010 classification by their mitotic index or Ki-67 index as G1, G2, or G3. The present study examined the efficacy of endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration (EUS-FNA) in the diagnosis and grading of pNET.
  
  
  METHODS
  We retrospectively reviewed 61 pNETs in 51 patients who underwent EUS between January 2007 and June 2014. All lesions were pathologically diagnosed by surgical resection or EUS-FNA. We evaluated the detection rates of EUS for pNET and sensitivity of EUS-FNA, and compared the Ki-67 index between EUS-FNA samples and surgical specimens. EUS findings were compared between G1 and G2/G3 tumors.
  
  
  RESULTS
  EUS showed significantly higher sensitivity (96.7%) for identifying pNET than CT (85.2%), MRI (70.2%), and ultrasonography (75.5%). The sensitivity of EUS-FNA for the diagnosis of pNET was 89.2%. The concordance rate of WHO classification between EUS-FNA and surgical specimens was 69.2% (9/13). The concordance rate was relatively high (87.5%, 5/6) in tumors <20 mm but lower (57.1%; 4/7) in tumors ≥20 mm. Regarding EUS findings, G2/G3 tumors were more likely to be large (>20 mm), heterogeneous, and have main pancreatic duct (MPD) obstruction than G1 tumors. Multivariate analysis showed large diameter and MPD obstruction were significantly associated with G2/G3 tumors.
  
  
  CONCLUSIONS
  EUS and EUS-FNA are highly sensitive and accurate diagnostic methods for pNET. Characteristic EUS findings such as large tumor size and MPD obstruction are suggestive of G2/G3 tumors and would be helpful for grading pNETs.
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .|b Department of Gastroenterology , Clinical Research Institute, National Hospital Organization Kyushu Medical Center , Fukuoka , Japan , and.
authors.forename: Nao
authors.initials: N
authors.lastname: Fujimori
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .
authors.forename: Takashi
authors.initials: T
authors.lastname: Osoegawa
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .
authors.forename: Lingaku
authors.initials: L
authors.lastname: Lee
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tachibana
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .
authors.forename: Akira
authors.initials: A
authors.lastname: Aso
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kubo
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .|b Department of Gastroenterology , Clinical Research Institute, National Hospital Organization Kyushu Medical Center , Fukuoka , Japan , and.
authors.forename: Ken
authors.initials: K
authors.lastname: Kawabe
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .
authors.forename: Hisato
authors.initials: H
authors.lastname: Igarashi
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: c Department of Anatomic Pathology , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
authors.affiliation: a Department of Medicine and Bioregulatory Science , Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan .
authors.forename: Tetsuhide
authors.initials: T
authors.lastname: Ito
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D060787:Neoplasm Grading; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D010183:Pancreatic Ducts / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D047368:Tumor Burden; D055815:Young Adult
keywords: EUS-FNA; Endoscopic ultrasonography (EUS); pancreatic neuroendocrine tumors