The prognostic role of proliferation activity in human CNS tumours: the determination of AgNOR, PCNA and Ki-67 expression. Part 1: AgNOR expression in CNS tumours.

The aim of the study was an evaluation of the proliferation activity of Central Nervous System tumours by using silver colloid staining of nucleolar organiser regions (AgNORs) and comparing the results with the proliferation activity estimated by using PCNA and Ki-67 antibodies to clarify the clinicopathological significance of this method. The first part of the study describes the results of AgNOR expression and its correlation with the histological type and grading of the tumours. The study group comprised samples from 204 cases of CNS tumours and 10 cases of post-traumatic neuroma. The analysis of staining results with the use of a computerised image analysis system revealed significant differences between the expression of AgNOR in CNS tumours of different grades. A spectrum of gradually increasing AgNOR expression from benign to low and high grade tumours indicates that the AgNOR staining method can be a useful supplement to the histopathological diagnostics of CNS tumours.