Estrogen receptors alpha and beta immunohistochemical expression: clinicopathological correlations in pituitary adenomas.
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.
Manoranjan
B
B
Department of Laboratory Medicine, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada.
Salehi
F
F
Scheithauer
B W
BW
Rotondo
F
F
Kovacs
K
K
Cusimano
M D
MD
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*
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta