title: Combined yolk sac tumor and adenocarcinoma in a gastric stump: molecular evidence of clonality.
abstract: BACKGROUND
  Extragonadal yolk sac tumors of the gastrointestinal tract are extremely rare neoplasms. Their greater rarity compared with other extragonadal yolk sac tumors suggests that different pathogenetic mechanisms could be involved according to the site of origin. This report describes a case of a combined yolk sac tumor and adenocarcinoma that arose in a gastric stump in a man age 61 years 43 years after he underwent distal gastric resection and gastrojejunostomy (Billroth II operation) for a benign duodenal ulcer. The coexistence of an adenocarcinomatous component with the yolk sac component suggests that the two histologic patterns may represent distinct phenotypes arising from a common mucosal epithelial cell.
  
  
  METHODS
  Immunohistochemical and molecular techniques were used to define the mutation pattern of p53 in both components of the tumor.
  
  
  RESULTS
  Single-strand conformation polymorphism and sequencing analyses demonstrated the same pattern of p53 mutation in the adenocarcinomatous and yolk sac tumor components.
  
  
  CONCLUSIONS
  This finding suggests that the two tumors could have been derived from the same cellular clone and supports the hypothesis that the two components represented a heterogeneous differentiation of the same tumor.
authors.affiliation: Department of Medical and Morphological Research, Institute of Clinical Oncology, University of Udine, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Puglisi
authors.forename: G
authors.initials: G
authors.lastname: Damante
authors.forename: S
authors.initials: S
authors.lastname: Pizzolitto
authors.forename: L
authors.initials: L
authors.lastname: Mariuzzi
authors.forename: S
authors.initials: S
authors.lastname: Guerra
authors.forename: L
authors.initials: L
authors.lastname: Pellizzari
authors.forename: F
authors.initials: F
authors.lastname: Binotto
authors.forename: C A
authors.initials: CA
authors.lastname: Beltrami
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology; D002999:Clone Cells; D004273:DNA, Neoplasm / Q000235:genetics; D018240:Endodermal Sinus Tumor / Q000235:genetics* / Q000473:pathology; D018530:Gastric Stump / Q000473:pathology*; D016158:Genes, p53; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009378:Neoplasms, Multiple Primary / Q000235:genetics* / Q000473:pathology; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology; D013276:Stomach Ulcer / Q000601:surgery
chemical_list: D004273:DNA, Neoplasm