title: Serotonin-producing enterochromaffin cell tumors of the pancreas: clinicopathologic study of 15 cases and comparison with intestinal enterochromaffin cell tumors.
abstract: OBJECTIVE
  Serotonin-producing tumors of the pancreas are rare endocrine neoplasms composed of enterochromaffin (EC) cells that have been mainly described in the literature as case reports. This study analyzes the clinicopathologic features of a series of pancreatic EC cell neoplasms and their similarities to and differences from intestinal EC cell tumors.
  
  
  METHODS
  The morphological, immunohistochemical, ultrastructural, and fluorescent in situ hybridization features of 15 pancreatic and 20 intestinal serotonin-producing neoplasms were compared. In addition, we reviewed the literature on pancreatic serotonin-producing tumors to better understand the clinicopathologic features of this rare tumor type.
  
  
  RESULTS
  The lack of substance P and acidic fibroblast growth factor immunoreactivity; the low immunohistochemical expression of CDX2, vesicular monoamine transporter 1, connective tissue growth factor, and prostatic acid phosphatase; the lack of S100-positive sustentacular cells; the strong expression of vesicular monoamine transporter 2; and peculiar ultrastructural features characterize pancreatic EC cell tumors and differentiate them from intestinal ones, although both categories show similar chromosome 18 cytogenetic alterations. The review of the literature indicates that pancreatic functioning tumors associated with the carcinoid syndrome arise in younger patients and are larger, more frequently malignant, and more aggressive neoplasms than pancreatic nonfunctioning ones.
  
  
  CONCLUSIONS
  Pancreatic EC cell tumors show several different morphological features compared with related intestinal tumors despite similar cytogenetic alterations on chromosome 18.
authors.affiliation: Department of Pathology, Ospedale di Circolo, Varese, Italy. stefano.larosa@ospedale.varese.it
authors.forename: Stefano
authors.initials: S
authors.lastname: La Rosa
authors.forename: Francesca
authors.initials: F
authors.lastname: Franzi
authors.forename: Luca
authors.initials: L
authors.lastname: Albarello
authors.forename: Anja
authors.initials: A
authors.lastname: Schmitt
authors.forename: Barbara
authors.initials: B
authors.lastname: Bernasconi
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Tibiletti
authors.forename: Giovanna
authors.initials: G
authors.lastname: Finzi
authors.forename: Claudia
authors.initials: C
authors.lastname: Placidi
authors.forename: Aurel
authors.initials: A
authors.lastname: Perren
authors.forename: Carlo
authors.initials: C
authors.lastname: Capella
mesh_terms: D000328:Adult; D000368:Aged; D002276:Carcinoid Tumor / Q000378:metabolism* / Q000473:pathology*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics; D004759:Enterochromaffin Cells / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007414:Intestinal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D053208:Kaplan-Meier Estimate; D008297:Male; D008303:Malignant Carcinoid Syndrome / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D012701:Serotonin / Q000096:biosynthesis*
chemical_list: D012701:Serotonin