artigo original Avaliação da Atividade Secretora, Proliferação Celular e Expressão da Proteína p27 em Tumores Hipofisários

The aim of this study was to evaluate the secretory activity, cell proliferation and inhibition of the cell cycle of pituitary neoplasm. Tissues were obtained from 13 patients presenting with acromegaly (n=5), non-secreting adenomas (n=4), hyperprolactinemia (n=3) and Cushing's disease (n=1). Specimens were examined by an immunohistochemical technique using anti-ACTH, anti-TSH, anti-LH, anti-FSH, anti-PRL, anti-hGH, antiMIB-1 (analysis of cell proliferation) and anti-p27 (analysis of cell cycle inhibition) antibodies. Regarding secretory activity all tumors produced more than one hormone. Cells positive for MIB-1 were present in approximately 46% of the cases. The highest incidence of proliferation was found in those presenting acromegaly (80% of the cases). Expression of the p27 protein was positive in approximately 38%, being on an average, highest in Cushing's disease. These results demonstrate the presence of multisecretory pituitary adenomas, a relative common finding. The relatively low cell proliferation indexes and the near normal tissue levels of p27 confirm that these tumors grow at a rather slow rate. (Arq Bras Endocrinol Metab 2000;44/5: 397-404)