Immunohistochemistry for pituitary hormones and Ki-67 in growth hormone producing pituitary adenomas Evaluación por inmunohistoquímica de la expresión de hormonas hipofisiarias y del marcador de proliferación celular Ki-67 en tejido de adenomas causantes

Background: Growth hormone (GH) producing adenomas, frequently express several hormones. This condition could confer them a higher proliferative capacity. Ki-67 is a nuclear protein antigen that is a marker for proliferative activity. Aim: To measure the immunohistochemical hormone expression in pituitary adenomas, excised from patients with acromegaly. To determine if the plurihormonal condition of these adenomas is associated with a higher proliferative capacity, assessed through the expression of Ki-67. Material and methods: Forty one paraffin embedded surgical samples of pituitary adenomas from patients with acromegalia were studied. Immunohistochemistry for GH, prolactin (PRL), follicle stimulating hormone (FSH), luteinizing hormone (LH), thyroid stimulating hormone (TSH), adrenocorticotropin (ACTH) and for the expression of Ki-67 was carried out. Results: All samples were positive for GH. Twenty seven had positive staining for PRL, 12 had positive staining for glycoproteic hormo