Is the Real Prevalence of Pancreatic Neuroendocrine Tumors Underestimated? A Retrospective Study on a Large Series of Pancreatic Specimens

Neuroendocrinology. 2019;109(2):165-170. doi: 10.1159/000499606. Epub 2019 May 22.


Background/aims: The annual incidence of pancreatic neuroendocrine tumors (PanNET) has been estimated to be around 0.8/100,000 inhabitants. The aim of this study was to determine the frequency of incidental histological diagnosis of PanNET in pancreatic specimen evaluation for a purpose other other than PanNET diagnosis.

Methods: One thousand seventy-four histopathological examinations of pancreatic specimens performed in 3 centers in Italy were retrospectively reviewed. All cases with a main pathological diagnosis of PanNET were excluded.

Results: An incidental associated diagnosis of PanNET was made in 41 specimens (4%). Among those 41 cases, 29 (71%) had a largest diameter <5 mm (microadenoma), whereas the other 12 (29%) had a maximum size ≥5 mm (median diameter of the whole series = 3 mm, range 1-15). The association with a main diagnosis of intraductal papillary mucinous neoplasms (IPMN) was significantly higher for patients who had an incidental PanNET (p = 0.048). There was no association between incidental diagnosis of PanNET and age, gender, BMI, smoking habit, diabetes, and type of operation.

Conclusions: The frequency of incidental histological diagnosis of PanNET is considerably high, suggesting that their real prevalence is probably underestimated. The present study suggests a possible correlation between the incidental occurrence of PanNET and IPMN.

Keywords: Histology; Incidental diagnosis; Pancreatic neuroendocrine tumor.

Publication types

  • Multicenter Study
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biological Specimen Banks / statistics & numerical data
  • Female
  • Humans
  • Incidence
  • Incidental Findings*
  • Italy / epidemiology
  • Male
  • Middle Aged
  • Neuroendocrine Tumors / diagnosis
  • Neuroendocrine Tumors / epidemiology*
  • Neuroendocrine Tumors / pathology
  • Pancreatic Neoplasms / diagnosis
  • Pancreatic Neoplasms / epidemiology*
  • Pancreatic Neoplasms / pathology
  • Prevalence
  • Retrospective Studies