Nucleolar organizer regions in pituitary adenomas.

In this study, thirty-two non-functional and eighteen functional pituitary adenomas were analysed for the presence of argyrophilic nucleolar organizer regions (Ag-NORs) in paraffin sections, using an one-step silver-colloidal staining method. Differences in the mean Ag-NOR numbers of functional pituitary adenomas were statistically significant than those of non-functional pituitary adenomas. It is being emphasised that evaluation of Ag-NOR count is a more reliable index than the presence of mitotic figures in predicting the proliferative activity as well as possibility of recurrence in a patient with pituitary adenoma.