title: A case of mixed adenoneuroendocrine carcinoma of the pancreas: Immunohistochemical analysis for histogenesis.
abstract: BACKGROUND
  Tumors with multiple histological features, such as adenocarcinomas and neuroendocrine carcinomas, were included as a new category of neuroendocrine carcinomas in the 2010 World Health Organization classification. We recently experienced a rare case of a pancreatic carcinoma with both adenocarcinoma and neuroendocrine carcinoma components, a so-called mixed adenoneuroendocrine carcinoma.
  
  
  METHODS
  A 66-year-old man was referred to our hospital with obstructive jaundice. Contrast-enhanced computed tomography images indicated a tumor located at the pancreatic head measuring 3.0 × 2.5 cm in diameter and invading the common bile duct. Cytological examination of the bile juice obtained by endoscopic retrograde cholangiopancreatography revealed adenocarcinoma cells. Pancreaticoduodenectomy was performed safely as radical resection.
  
  
  METHODS
  Microscopically, the resected tumor consisted of tightly intermingled adenocarcinoma and neuroendocrine carcinoma components. On the immunohistochemical examination, p53 was ubiquitously positive in both components, whereas chromogranin A, synaptophysin and neuron-specific enolase, neuroendocrine markers, were limited to the neuroendocrine carcinoma component.
  
  
  RESULTS
  Thus, such features of both adenocarcinoma and neuroendocrine carcinoma observed microscopically and immunohistochemically seemed to indicate a composite tumor.
  
  
  CONCLUSIONS
  The findings of this case suggest that adenocarcinoma and neuroendocrine carcinoma may be derived from a single cancer stem cell.
authors.affiliation: Department of Surgery Department of Pathology, Itami City Hospital, Itami-shi, Hyogo, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Murata
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Moyuru
authors.initials: M
authors.lastname: Yamada
authors.forename: Misa
authors.initials: M
authors.lastname: Song
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hiratsuka
mesh_terms: D000368:Aged; D018278:Carcinoma, Neuroendocrine / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D010179:Pancreas / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed