title: Four Neuroendocrine Tumor Types and Neuroendocrine Carcinoma of the Duodenum: Analysis of 203 Cases.
abstract: BACKGROUND
  Several types of neuroendocrine neoplasms (NENs) have been described in the duodenal tract, from low-grade tumors (NETs) to high-grade neuroendocrine carcinomas (NECs). A comprehensive analysis of histology, hormonal profile and prognostic parameters of a sufficiently large duodenal NEN series to cover all main kinds of neoplasms is however lacking.
  
  
  METHODS
  We collected a retrospective series of 203 duodenal wall and ampullary region NENs, from six specialized endocrine pathology centers. All were characterized histopathologically and histochemically, and 190 were followed for a median of 9 years.
  
  
  RESULTS
  Twenty-seven poorly differentiated NECs, mostly from the ampullary region, were identified and shown to lead to patient demise in a median of 10 months. Among 176 NETs, four subtypes were characterized, including 20 gastrinomas, 37 ampullary-type somatostatin-producing NETs (ASTs), 12 gangliocytic paragangliomas (GPs) and 106 nonfunctioning NETs (nfNETs). ASTs and GPs were mostly localized in the ampullary/periampullary region, while gastrinomas and nfNETs were mainly from the proximal duodenum. ASTs and gastrinomas showed high rates of local infiltration (especially lymphoinvasion and deep duodenal wall/pancreatic tissue invasion) and lymph node metastasis, while nfNETs had significantly lower and more size-dependent local invasive potential. Disease-specific survival differed significantly between NETs and NECs, though not among NET subtypes. NET cases with distant metastases (n = 23) were significantly associated with larger size, higher proliferative grade, lymphovascular invasion, deep invasion and local lymph node metastasis.
  
  
  CONCLUSIONS
  Our careful analysis of a large series of duodenal NENs identified five histologically and prognostically different histotypes of potential clinical relevance.
authors.affiliation: Division of Pathology, Department of Molecular Medicine, University of Pavia and Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vanoli
authors.forename: Stefano
authors.initials: S
authors.lastname: La Rosa
authors.forename: Catherine
authors.initials: C
authors.lastname: Klersy
authors.forename: Federica
authors.initials: F
authors.lastname: Grillo
authors.forename: Luca
authors.initials: L
authors.lastname: Albarello
authors.forename: Frediano
authors.initials: F
authors.lastname: Inzani
authors.forename: Roberta
authors.initials: R
authors.lastname: Maragliano
authors.forename: Rachele
authors.initials: R
authors.lastname: Manca
authors.forename: Ombretta
authors.initials: O
authors.lastname: Luinetti
authors.forename: Massimo
authors.initials: M
authors.lastname: Milione
authors.forename: Claudio
authors.initials: C
authors.lastname: Doglioni
authors.forename: Guido
authors.initials: G
authors.lastname: Rindi
authors.forename: Carlo
authors.initials: C
authors.lastname: Capella
authors.forename: Enrico
authors.initials: E
authors.lastname: Solcia
mesh_terms: D000368:Aged; D018278:Carcinoma, Neuroendocrine / Q000453:epidemiology* / Q000473:pathology*; D004379:Duodenal Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D018358:Neuroendocrine Tumors / Q000453:epidemiology* / Q000473:pathology*; D012189:Retrospective Studies; D016019:Survival Analysis