title: Significance of occult neoplastic cells on tumor metastasis: a case report of gastric cancer.
abstract: BACKGROUND
  Occult neoplastic cells (ONCs) are the tumor cells floating in the lymph node sinuses, distant from the primary tumor, and supposed to be one of most reliable marker of prognosis.
  
  
  METHODS
  We report here the case of a 52-year-old woman with a gastric cancer associated by numerous ONCs.
  
  
  RESULTS
  Postoperative examination of the stomach disclosed an advanced, poorly differentiated adenocarcinoma with frequent lymph node metastases. In addition to ONCs and occasional micrometastases, focal aggregates of ONCs, one of the possible intermediate lesions between the ONCs and the usual metastases, are also observed.
  
  
  CONCLUSIONS
  In the present case, at least some of ONCs seem to form the microaggregates of tumor cells in lymph nodes, anchor in the sinuses, and grow up to the large tumorous lesion. Even if most of the ONCs were trapped and disappeared under the influence of tumor immunity, the detection of ONCs could be one of the reliable clues to estimate the prognosis.
authors.affiliation: Department of Pathology, Tokai University Oiso Hospital, 21-1 Gakyou, Oiso, Kanagawa, Japan. sato@oiso.u-tokai.ac.jp
authors.forename: Shinkichi
authors.initials: S
authors.lastname: Sato
authors.forename: Masaya
authors.initials: M
authors.lastname: Mukai
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D001706:Biopsy; D018279:Carcinoma, Signet Ring Cell / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D002454:Cell Differentiation; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000556:secondary; D017809:Fatal Outcome; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D005743:Gastrectomy; D006801:Humans; D007150:Immunohistochemistry; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D000964:Antimetabolites, Antineoplastic; D005472:Fluorouracil