title: Endoglin and CD-34 immunoreactivity in the assessment of microvessel density in normal pituitary and adenoma subtypes.
abstract: Vascularization is a prerequisite of tumor growth, invasion and metastasis. In the present work, microvessel density was assessed by quantitating using two different endothelial cell biomarkers, endoglin (CD-105) and CD-34. Fifty endocrinologically active and 36 clinically nonfunctioning pituitary adenomas, all surgically resected, as well as 10 autopsy-derived normal adenohypophyses were investigated by immunohistochemistry. The results showed that in every pituitary adenoma type endoglin, an assumed biomarker of proliferating endothelial cells, immunostained fewer vessels than CD-34 which revealed immunopositivity in all capillaries. Differences in endoglin versus CD-34 immunoexpression indicate varying degrees of vascularity in pituitary adenoma subtypes. The low levels of endoglin immunoexpression in pituitary tumors exposed to long-acting somatostatin analogs and dopamine agonists are consistent with the view that these agents inhibit angiogenesis.
  
  
  BACKGROUND
  immunohistochemistry, endoglin, CD34, microvascular density, angiogenesis, pituitary.
authors.affiliation: Department of Laboratory Medicine, University of Toronto, Toronto, ON, Canada. rotondof@smh.ca
authors.forename: F
authors.initials: F
authors.lastname: Rotondo
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.forename: B W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: E
authors.initials: E
authors.lastname: Horvath
authors.forename: L V
authors.initials: LV
authors.lastname: Syro
authors.forename: M
authors.initials: M
authors.lastname: Cusimano
authors.forename: F
authors.initials: F
authors.lastname: Nassiri
authors.forename: G M
authors.initials: GM
authors.lastname: Yousef
authors.forename: K
authors.initials: K
authors.lastname: Kovacs
mesh_terms: D000236:Adenoma / Q000098:blood supply* / Q000737:chemistry; D015703:Antigens, CD / Q000032:analysis*; D018952:Antigens, CD34 / Q000032:analysis*; D000071063:Endoglin; D006801:Humans; D007150:Immunohistochemistry; D055806:Microvessels / Q000737:chemistry; D010902:Pituitary Gland / Q000098:blood supply*; D010911:Pituitary Neoplasms / Q000098:blood supply* / Q000737:chemistry; D011956:Receptors, Cell Surface / Q000032:analysis*
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; C064206:ENG protein, human; D000071063:Endoglin; D011956:Receptors, Cell Surface