title: Estrogen receptors alpha and beta immunohistochemical expression: clinicopathological correlations in pituitary adenomas.
abstract: OBJECTIVE
  We investigated the immunohistochemical expression of estrogen receptors alpha (ERalpha) and beta (ERbeta) in pituitary adenoma subtypes combined with clinicopathological factors.
  
  
  METHODS
  Pituitary adenomas (n=75) were immunostained for ERalpha and ERbeta using the streptavidin-biotin-peroxidase complex method with a monoclonal ERalpha antibody and polyclonal ERbeta antibody.
  
  
  RESULTS
  Nuclear immunoreactivity for both receptors was highest among PRL, FSH/LH, null cell, and GH adenomas. ACTH, silent subtypes I and II corticotrophs, and subtype III adenomas were the least immunoreactive for both receptors. ACTH adenomas expressed significantly less ERalpha than FSH-LH, GH, and null cell adenomas. A significantly elevated ERalpha expression was observed in macroadenomas compared to microadenomas and non-invasive compared to invasive tumors.
  
  
  CONCLUSIONS
  ERalpha and ERbeta are differentially expressed in the various pituitary adenoma subtypes suggesting a cell-specific function for these receptors. To elucidate the role of ERalpha in tumor size and invasiveness, additional studies are required.
authors.affiliation: Department of Laboratory Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Manoranjan
authors.forename: F
authors.initials: F
authors.lastname: Salehi
authors.forename: B W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: F
authors.initials: F
authors.lastname: Rotondo
authors.forename: K
authors.initials: K
authors.lastname: Kovacs
authors.forename: M D
authors.initials: MD
authors.lastname: Cusimano
mesh_terms: D000236:Adenoma / Q000378:metabolism* / Q000473:pathology*; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000096:biosynthesis* / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000096:biosynthesis* / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009361:Neoplasm Invasiveness; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000473:pathology*
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta