title: Immunohistochemical detection of estrogen receptor alpha in pituitary adenomas and its correlation with cellular replication.
abstract: With the aim of evaluating the relationship between pituitary tumorigenesis and the presence of estrogen receptor-alpha (ERalpha) by immunohistochemistry (IH) and their relevance to patients' clinical presentation, hormonal phenotypes of adenomas, preoperative neuroimaging findings, and the index of cellular replication MIB-1, a study was conducted with material from 91 women and 67 men with pituitary adenomas. The patients had acromegaly (29.7%), Cushing's disease (14.6%), hyperprolactinemic syndrome (20.9%), and clinically nonfunctioning tumors (34.8%). Of the patients, 14.6% had microadenomas, 52.5% had macroadenomas with or without suprasellar growth, 28.5% had invasive macroadenomas and in 4.4% the adenoma was not visualized. IH showed that 43 were positive for growth hormone (GH), 16 for corticotropin (ACTH), 18 for prolactin (PRL), 18 for PRL+GH, 6 for luteinizing hormone (LH) and follicle-stimulating hormone (FSH), 15 had a plurihormonal reaction, and 42 had nonfunctioning adenomas. The presence of ERalpha was positive in 9/158 adenomas with a median value for the percentage of labeled cells of 42.89%, and in 6/16 controls (autopsy samples) with a median value for the percentage of labeled cells of 0.024%. ERalpha was significantly more prevalent in controls than in patients with adenomas (37.5 versus 5.7%; p = 0.001); however, the mean ERalpha concentration in adenomas was significantly greater than in controls (42.89 versus 0.024%; p < 0.001). No significant difference in the concentration of ERalpha was found across the clinical presentations, hormonal phenotypes or findings of preoperative CT. Among the ERalpha-positive adenomas, ERalpha values were significantly greater in invasive macroadenomas (80%) than in microadenomas (3.33%). MIB-1 values did not differ significantly between ERalpha-positive and -negative adenomas, nor did the correlation between ERalpha values and the MIB-1 index attain significance in the total sample, even when only ERalpha-positive adenomas and positive MIB-1 indexes were considered. It was concluded that, when present in pituitary tumors, ERalpha exhibits a high concentration, and is more common in nonfunctioning and invasive adenomas, but absent in ACTH-secreting ones.
authors.affiliation: General and Experimental Pathology, Fundação Faculdade de Ciências Médicas, Porto Alegre, Brazil.
authors.forename: Julia F S
authors.initials: JF
authors.lastname: Pereira-Lima
authors.forename: Caroline P
authors.initials: CP
authors.lastname: Marroni
authors.forename: Cristina B
authors.initials: CB
authors.lastname: Pizarro
authors.forename: Ligia M
authors.initials: LM
authors.lastname: Barbosa-Coutinho
authors.forename: Nelson P
authors.initials: NP
authors.lastname: Ferreira
authors.forename: Miriam C
authors.initials: MC
authors.lastname: Oliveira
mesh_terms: D000236:Adenoma / Q000145:classification* / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D002455:Cell Division; D003430:Cross-Sectional Studies; D047628:Estrogen Receptor alpha; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000145:classification* / Q000378:metabolism* / Q000473:pathology; D011960:Receptors, Estrogen / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: D047628:Estrogen Receptor alpha; D019394:Ki-67 Antigen; D011960:Receptors, Estrogen