title: Diagnostic immunohistochemistry of cutaneous metastatic breast carcinoma: a statistical analysis of the utility of gross cystic disease fluid protein-15 and estrogen receptor protein.
abstract: BACKGROUND
  For accurate classification of cutaneous metastatic carcinoma, reliable tumor-specific immunohistochemical markers would be valuable.
  
  
  OBJECTIVE
  Our purpose was to analyze the sensitivity, specificity, and positive predictive value of gross cystic disease fluid protein-15 (GCDFP-15) and estrogen receptor protein (ERP) for diagnosing cutaneous metastatic breast carcinoma.
  
  
  METHODS
  Tissue sections from 68 consecutive cases of cutaneous metastatic carcinoma were stained for GCDFP-15 and ERP. Hematoxylin-eosin-stained slides and immunostained slides were reviewed in a blinded fashion before retrospective chart review to ascertain the underlying primary tumor type.
  
  
  RESULTS
  Of 42 cases of cutaneous metastatic breast carcinoma, 30 were positive for GCDFP-15. Of 41 cases of metastatic breast carcinoma, 30 were positive for ERP. Calculated sensitivity, specificity, and positive predictive value for GCDFP-15 for diagnosing cutaneous metastatic breast carcinoma were 71%, 91%, and 94%, respectively, and 73%, 100%, and 100% for ERP, respectively. Combined values of these indices for both stains were 83%, 91%, and 95%, respectively.
  
  
  CONCLUSIONS
  GCDFP-15 and ERP are valuable markers for cutaneous metastatic breast carcinoma and should be used in combination.
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Ormsby
authors.forename: J L
authors.initials: JL
authors.lastname: Snow
authors.forename: W P
authors.initials: WP
authors.lastname: Su
authors.forename: J R
authors.initials: JR
authors.lastname: Goellner
mesh_terms: D001053:Apolipoproteins; D053399:Apolipoproteins D; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000473:pathology*; D002352:Carrier Proteins / Q000032:analysis*; D005260:Female; D006023:Glycoproteins; D006801:Humans; D007150:Immunohistochemistry; D026901:Membrane Transport Proteins; D011237:Predictive Value of Tests; D011960:Receptors, Estrogen / Q000032:analysis; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000556:secondary*
chemical_list: C024328:APOD protein, human; D001053:Apolipoproteins; D053399:Apolipoproteins D; D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D006023:Glycoproteins; D026901:Membrane Transport Proteins; C488892:PIP protein, human; D011960:Receptors, Estrogen; C010140:estrophilin