title: Mesothelial markers in high-grade breast carcinoma.
abstract: OBJECTIVE
  Advances in molecular profiling have subdivided breast carcinomas into distinct subtypes. Basal carcinomas are generally oestrogen receptor (ER)-progesterone receptor (PR)-/human epidermal growth factor receptor 2 (HER2)-, and cytokeratin (CK)5/6+. This profile overlaps with that of mesothelial cells. This study of high-grade breast carcinomas was undertaken to determine the expression of mesothelial markers.
  
  
  RESULTS
  Immunohistochemistry was performed on 23 basal-like breast carcinomas and 30 high-grade breast carcinomas with variable ER, PR and HER2 expression. The incidence of staining of CK5/6, CK14, calretinin, Wilms' tumour 1 (WT1), thrombomodulin and epithelial membrane antigen was assessed statistically. CK14 staining was more specifically associated with triple-negative tumours than CK5/6. Calretinin positivity was statistically associated with basal-like carcinomas. WT1 and thrombomodulin expression was infrequent and limited to a small number of non-basal carcinomas.
  
  
  CONCLUSIONS
  There is an overlap between the immunophenotype of mesothelial cells and that of basal-like carcinomas of breast. Positive calretinin and CK5/6 are not specific, and may be seen in both mesothelial cells and basal-like breast carcinomas. Negative ER and PR of basal carcinomas may also bias the observer against a breast origin. However, other negative mesothelial markers, such as WT1 and thrombomodulin, may help point to the correct diagnosis.
authors.affiliation: Department of Anatomical Pathology, Pathology Queensland, The Prince Charles Hospital, Chermside, Queensland, Australia. Edwina_Duhig@health.qld.gov.au
authors.forename: Edwina E
authors.initials: EE
authors.lastname: Duhig
authors.forename: Lydia
authors.initials: L
authors.lastname: Kalpakos
authors.forename: Ian A
authors.initials: IA
authors.lastname: Yang
authors.forename: Belinda E
authors.initials: BE
authors.lastname: Clarke
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D002277:Carcinoma / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D004848:Epithelium / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008875:Middle Aged; D060787:Neoplasm Grading
chemical_list: D014408:Biomarkers, Tumor