title: Pituitary macroadenomas (>3 cm) in young adulthood: Pathologic and proliferative characteristics.
abstract: BACKGROUND
  There are scarce data regarding the significance of the tumor size, hormonal activity and size of the pituitary tumor of the young; therefore, the study was designed to define the relation of the hormonal status of the large pituitary adenomas.
  
  
  OBJECTIVE
  We compared those features with tumors of the elderly (>40) with the young patients, and analyzed the clinicopathologic and proliferative features of pituitary macroadenomas in young adulthood (≤40).
  
  
  METHODS
  20-year archives of pituitary tumors in our clinics were reviewed and macroadenomas with diameter≥3 cm were included in the study. We identified 46 pituitary adenomas and immunohistochemically stained them with pituitary hormones, p53 and Ki-67. Twenty-four cases were ≤40-year with an age range of 11-40 years (mean 28.0). Twenty-two cases were >40 with an age range of 44-78 years (mean 58.8).
  
  
  RESULTS
  In the young patient group, 15 (62.5%) were functional adenomas (6 prolactinomas, six growth hormone [GH], one adrenocorticotrophic hormone [ACTH] adenoma, two multihormonal [GH+ACTH]) and nine (37.5%) were either gonadotrophic or null cell adenomas. In the elderly group, five (22.7%) were functional adenomas (two adrenocorticotrophic hormone [ACTH] adenoma, one prolactinoma, one growth hormone [GH], one multihormonal [GH+ACTH]) and 17 (77.3%) were either gonadotrophic or null cell adenomas. Ki-67 proliferation index in adenomas of the young was approximately two-folds higher than the elderly (2.7% vs. 1.2%).
  
  
  CONCLUSIONS
  In both groups, rare p53 positivity was identified. In conclusion, pituitary macroadenomas of the young show hormonal expression frequently with relatively high Ki-67 proliferation indices.
authors.affiliation: Department of Pathology, GATA Military Medical Academy, School of Medicine, Ankara, Turkey.
authors.forename: Önder
authors.initials: Ö
authors.lastname: Öngürü
authors.affiliation: Department of Neurosurgery, GATA Military Medical Academy, Haydarpaşa Training Hospital İstanbul, Turkey.
authors.forename: Bülent
authors.initials: B
authors.lastname: Düz
authors.affiliation: Department of Neurological Surgery, Johns Hopkins University Hospital, Baltimore, USA. Electronic address: drhakansimsek@hotmail.com.
authors.forename: Hakan
authors.initials: H
authors.lastname: Şimşek
authors.affiliation: Department of Pathology, GATA Military Medical Academy, School of Medicine, Ankara, Turkey.
authors.forename: Armağan
authors.initials: A
authors.lastname: Günal
authors.affiliation: Department of Neurosurgery, Tobb Etu Hospital, Ankara, Turkey.
authors.forename: Engin
authors.initials: E
authors.lastname: Gönül
mesh_terms: D000236:Adenoma / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D055815:Young Adult
chemical_list: D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53
keywords: Giant; Immunohistochemistry; Ki-67; Macroadenoma; Pituitary adenoma