title: Adenocarcinoma arising from gastric immature teratoma. Report of a case in an adult and a review of the literature.
abstract: BACKGROUND
  Gastric teratoma is an uncommon tumor and usually occurs in infancy or childhood. To the authors' knowledge, malignant transformation in gastric teratoma has not been reported previously.
  
  
  METHODS
  An 83-year-old Japanese man presented with a large polypoid gastric tumor composed of teratomatous components and invasive adenocarcinoma. Numerous blocks of this tumor were analyzed histologically and immunohistochemically.
  
  
  RESULTS
  Histologically, the gastric tumor consisted of teratomatous components with diverse maturation, such as fibroblastic mesenchymal cells, striated muscle cells, cartilaginous islands, neuroepithelial components, glial tissues, squamous cell nests, glandular components, and foci of adenocarcinoma infiltrating the benign gastric tissues adjacent to the tumor stalk. Metastatic foci of teratomatous components in the resected lymph nodes contained adenocarcinomatous glands. An immunohistochemical study helped confirm the differentiation in the immature components and the differential diagnosis between atypical neuroepithelial cells and the adenocarcinoma.
  
  
  CONCLUSIONS
  This study indicates that the adenocarcinoma arose from immature gastric teratoma. A review of the literature suggests that this is the oldest reported patient with gastric teratoma and to the authors' knowledge is the first report describing gastric teratoma with malignant transformation.
authors.affiliation: Department of Research and Laboratory, Japan Self Defense Forces Central Hospital, Tokyo.
authors.forename: S
authors.initials: S
authors.lastname: Matsukuma
authors.forename: R
authors.initials: R
authors.lastname: Wada
authors.forename: M
authors.initials: M
authors.lastname: Daibou
authors.forename: N
authors.initials: N
authors.lastname: Watanabe
authors.forename: N
authors.initials: N
authors.lastname: Kuwabara
authors.forename: H
authors.initials: H
authors.lastname: Abe
authors.forename: K
authors.initials: K
authors.lastname: Suda
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D013274:Stomach Neoplasms / Q000473:pathology*; D013724:Teratoma / Q000473:pathology*