title: [Metastatic cutaneous adenocarcinoma of unknown primary site. Case report].
abstract: BACKGROUND
  Metastases may be the first manifestation of adenocarcinoma. Up to 60% are cutaneous and present in advanced stage neoplasms. Research for the primary site is costly and requires endoscopy, imaging and immunohistochemical exams. The primary site becomes obvious in only 15% to 20% of live patients and is detected mainly at autopsy.
  
  
  OBJECTIVE
  To report a case of metastatic cutaneous moderately differentiated adenocarcinoma of unknown primary site, located in the lower left abdomen.
  
  
  RESULTS
  The lesion was surgically resected. Primary site was not found by any imaging or endoscopy exams. The immunohistochemistry was negative for CEA, CK20, PSA and positive for CK7. Based on these exams, prostate and colorectal cancer were excluded. The pancreas and biliary tract were considered as the probable primary site.
  
  
  CONCLUSIONS
  The research for the primary site still is difficult, expensive and is not effective to the treatment of metastatic adenocarcinomas.
authors.affiliation: Serviço de Cirurgia de Emergência, Divisão Cirúrgica III, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, Botucatu, SP. caionahas@uol.com.br
authors.forename: Caio Sergio Rizkallah
authors.initials: CS
authors.lastname: Nahas
authors.forename: Marcos Túlio Martino
authors.initials: MT
authors.lastname: Meniconi
authors.forename: Dario
authors.initials: D
authors.lastname: Birolini
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary* / Q000628:therapy; D000368:Aged; D001706:Biopsy; D006801:Humans; D008297:Male; D009382:Neoplasms, Unknown Primary / Q000473:pathology* / Q000628:therapy; D012878:Skin Neoplasms / Q000556:secondary* / Q000628:therapy