Recurrence of meningiomas versus proliferating cell nuclear antigen (PCNA) positivity and AgNOR counting.

Meningiomas have a wide range of biological potential and clinical behaviour. Histological findings are helpful in recognizing the malignant potential but often fail to correlate with clinical behaviour. This study attempts to correlate the silver nucleolar organizer regions (AgNORs) and proliferating cell nuclear antigen (PCNA) with clinicopathological features of biological activity. Thirty-four completely resected meningiomas were classified as benign [19], atypical [6] and malignant [9]. Forty-eight initial and recurrent tumour materials were investigated for staining of AgNORs and immunohistochemistry using monoclonal antibodies against PCNA (clone 19A2 and PC10). There were no difference between the recurrent and non-recurrent cases with regards to AgNOR, PC10 and 19A2 values. Also, no significant difference was found between the primary and recurrent tumours. Both PC10 and 19A2 labelling indices (LI) showed a significant difference between benign and malignant meningiomas. The 19A2 LI was 0.56 +/- 0.21 in benign and 2.45 +/- 16 in atypical meningiomas. The 19 A2 counts showed significant difference between benign and atypical tumours but PC10 values failed to show such a correlation AgNOR and PCNA indices were not found to be useful in predicting recurrences compared to the surgical procedure and histopathological criteria.