title: A comprehensive comparison of clinicopathologic and imaging features of incidental/symptomatic non-functioning pancreatic neuroendocrine tumors: A retrospective study of a single center.
abstract: BACKGROUND
  Incidentally discovered, nonfunctioning pancreatic endocrine tumors (NF-pNETs) are being increasingly diagnosed with the widespread use of imaging examination. The objective of this study was to analyze the different clinicopathologic and imaging features between incidentally discovered and symptomatic NF-pNETs.
  
  
  METHODS
  From March 2010 to October 2014, we retrospectively analyzed 102 patients with pathologically confirmed sporadic NF-pNETs, among which 49 (48.0%) had lesions that were discovered incidentally. Differences in clinicopathologic features and various computerized tomography (CT) and endoscopic ultrasonography (EUS) findings were evaluated between incidental and symptomatic NF-pNETs.
  
  
  RESULTS
  Among 102 patients with NF-pNETs, 49 (48.0%) had lesions that were discovered incidentally. Incidental NF-pNETs were more highly associated with low tumor grades, stages and lymphatic metastasis compared with symptomatic tumors (p = 0.007, 0.029 and 0.003, respectively). Moreover, incidental NF-pNETs had a lower rate of hypoenhancement (p = 0.018), main pancreatic duct dilatation (p = 0.043), and unclear border (p = 0.022). In addition, hypoechoic lesion was the most common and had a slightly higher rate in symptomatic tumors (p = 0.032).
  
  
  CONCLUSIONS
  Incidental NF-pNETs are associated with lower rates of aggressive behaviors of clinicopathologic and imaging features compared with symptomatic tumors.
authors.affiliation: Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, PR China; Pancreatic Cancer Institute, Fudan University, Shanghai 200032, PR China.
authors.forename: Guopei
authors.initials: G
authors.lastname: Luo
authors.affiliation: Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
authors.forename: Zuqiang
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Pancreatic Cancer Institute, Fudan University, Shanghai 200032, PR China.
authors.forename: Meng
authors.initials: M
authors.lastname: Guo
authors.affiliation: Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
authors.forename: Kaizhou
authors.initials: K
authors.lastname: Jin
authors.affiliation: Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Xiao
authors.affiliation: Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, PR China; Pancreatic Cancer Institute, Fudan University, Shanghai 200032, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, PR China; Pancreatic Cancer Institute, Fudan University, Shanghai 200032, PR China.
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, PR China; Pancreatic Cancer Institute, Fudan University, Shanghai 200032, PR China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, PR China; Pancreatic Cancer Institute, Fudan University, Shanghai 200032, PR China.
authors.forename: Quanxing
authors.initials: Q
authors.lastname: Ni
authors.affiliation: Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, PR China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China; Pancreatic Cancer Institute, Fudan University, Shanghai 200032, PR China. Electronic address: surgeonlong@fudan.edu.cn.
authors.forename: Jiang
authors.initials: J
authors.lastname: Long
authors.affiliation: Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, Shanghai 200032, PR China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China; Pancreatic Cancer Institute, Fudan University, Shanghai 200032, PR China. Electronic address: yuxianjun88@hotmail.com.
authors.forename: Xianjun
authors.initials: X
authors.lastname: Yu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019160:Endosonography; D005260:Female; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000175:diagnosis*; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D011446:Prospective Studies; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: Clinicopathologic features; Imaging features; Incidental; Non-function pancreatic neuroendocrine tumors; Prognosis; Symptomatic