title: [Immunohistochemical flow chart to differentiate between primary adenocarcinoma and the most frequent extragynecological metastases in the ovary].
abstract: BACKGROUND
  The pathological differential diagnosis between primary and metastatic ovarian malignant tumors is usually difficult, specially for tumors originating in the gastrointestinal system or breast.
  
  
  OBJECTIVE
  To define an immunohistochemical flow chart to discriminate these tumor types.
  
  
  METHODS
  We performed a immunostaining analysis using a panel of six antibodies (CK 7, CA 125, CEA, CK20, BRST-2 and CA 15-3) in 3 tumor groups: 11 ovarian, 14 breast and 12 colonic primary tumors and in a study group of 38 ovarian tumors whose primary origin was unknown.
  
  
  RESULTS
  We defined an ovarian immunohistochemical pattern (CEA-/CK20-, 45% in ovarian tumors, 0% in breast or colonic tumors, p < 0.001); an ovary/breast pattern (CEA+/CK20-, 0% in colonic tumors, p < 0.001): a breast pattern (CEA+/CK20-/BKST-2+, 64% in breast tumors and 0% in colonic and ovarian tumors, p < 0.001) and a colonic pattern (CEA+/CK20+/CK7-, 67% in colonic tumors and 0% in breast and ovarian tumors, p < 0.001).
  
  
  CONCLUSIONS
  Employing a simple panel of antibodies, characteristic immunohistochemical patterns were defined for ovarian, breast and colonic tumors. These patterns allowed the identification of the origin of most tumors of the study group.
authors.affiliation: Departamentos de Anatomía Patológica y de Obstetricia y Ginecología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago, Chile. ypires@med.puc.cl
authors.forename: Yumay
authors.initials: Y
authors.lastname: Pires
authors.forename: Leonardo
authors.initials: L
authors.lastname: Andrade
authors.forename: Mauricio
authors.initials: M
authors.lastname: Cuello
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Chuaqui
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology* / Q000556:secondary; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000276:immunology / Q000473:pathology*; D003110:Colonic Neoplasms / Q000276:immunology / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D009382:Neoplasms, Unknown Primary / Q000276:immunology / Q000473:pathology; D010051:Ovarian Neoplasms / Q000276:immunology / Q000473:pathology* / Q000556:secondary; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor