title: Differential diagnosis of non-functional islet cell tumor and pancreatic carcinoma with sonography.
abstract: OBJECTIVE
  To investigate the differential diagnosis of non-functional islet cell tumor (NFICT) and pancreatic ductal adenocarcinoma (pancreatic carcinoma) with clinical presentation and sonographic features.
  
  
  METHODS
  Twenty cases of NFICT were investigated in the study, and 41 cases of pancreatic carcinoma were included as the control group. Among them, 5 NFICT and 32 pancreatic carcinomas underwent CEUS with SonoVue. Clinical presentation and sonographic characteristics were evaluated with Logistic regression analysis. Furthermore, the preliminary result of contrast enhanced ultrasound (CEUS) was analyzed.
  
  
  RESULTS
  Statistic analysis showed four significant factors in differential diagnosis for NFICT and pancreatic carcinoma, including age (P<0.001), tumor size (P=0.006), tumor margin (P<0.001) and vascularity of tumor (P=0.004). Combined these four factors, the sensitivity, specificity and accuracy are 95.0%, 95.1% and 95.1%, respectively. When the patient is younger than 60 years, and tumor is smaller than 5 cm with well-defined margin and hypervascular, it would be most likely a NFICT other than pancreatic carcinoma. NFICT often shows early enhancement and more homogeneous infusion than pancreatic carcinoma on CEUS (P=0.005 and 0.008).
  
  
  CONCLUSIONS
  Sonography is able to provide useful differential information for NFICT, which is often misdiagnosed as pancreatic carcinoma.
authors.affiliation: Department of Ultrasound, School of Oncology, Peking University, Beijing 100036, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Min-Hua
authors.initials: MH
authors.lastname: Chen
authors.forename: Kun
authors.initials: K
authors.lastname: Yan
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.forename: Ying
authors.initials: Y
authors.lastname: Dai
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
mesh_terms: D007516:Adenoma, Islet Cell / Q000175:diagnosis*; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis*; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D010743:Phospholipids; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012737:Sex Factors; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride