title: Mixed Adenoneuroendocrine Carcinoma, Amphicrine Type, of the Small Bowel.
abstract: OBJECTIVE
  Amphicrine-type mixed adenoneuroendocrine carcinomas are exceedingly rare lesions of the gastrointestinal tract, comprising tumor cells simultaneously demonstrating both neuroendocrine and exocrine features. To date, only 14 cases of amphicrine carcinoma have been reported; here we report the first definitive case of amphicrine carcinoma in the small bowel.
  
  
  METHODS
  A 72-year-old woman who sought treatment for nonspecific abdominal complaints was found to have a duodenojejunal junction tumor and underwent radical surgical resection.
  
  
  RESULTS
  Morphologically, the tumor consisted of areas of moderately differentiated adenocarcinoma intermingled with areas characteristic of neuroendocrine tumor. The entire tumor showed strong, diffuse immunoreactivity for synaptophysin. Coexpression of exocrine and neuroendocrine features by neoplastic cells indicates bivalent differentiation, and therefore the tumor was classified as an amphicrine carcinoma of the small bowel.
  
  
  CONCLUSIONS
  Demonstration of amphicrine carcinoma in the small bowel carries implications with regard to the common origin of exocrine and neuroendocrine cells in the gastrointestinal tract.
authors.affiliation: From the Department of Pathology, Duke University Medical Center, Durham, NC.
authors.forename: Ethan B
authors.initials: EB
authors.lastname: Ludmir
authors.affiliation: From the Department of Pathology, Duke University Medical Center, Durham, NC.
authors.forename: Shannon J
authors.initials: SJ
authors.lastname: McCall
authors.affiliation: From the Department of Pathology, Duke University Medical Center, Durham, NC.
authors.forename: Diana M
authors.initials: DM
authors.lastname: Cardona
authors.affiliation: From the Department of Pathology, Duke University Medical Center, Durham, NC.
authors.forename: Kathryn R
authors.initials: KR
authors.lastname: Perkinson
authors.affiliation: From the Department of Pathology, Duke University Medical Center, Durham, NC.
authors.forename: Cynthia D
authors.initials: CD
authors.lastname: Guy
authors.affiliation: From the Department of Pathology, Duke University Medical Center, Durham, NC. xuefeng.zhang@dm.duke.edu.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry
chemical_list: D014408:Biomarkers, Tumor
keywords: Adenocarcinoma; Amphicrine carcinoma; Mixed adenoneuroendocrine carcinoma; Neuroendocrine tumor; Small bowel cancer