Invasive meningiomas in relation to high proliferating potential.

We conducted a study to investigate whether an association exists among histologic findings, labeling index determined by the labeling index (LI) of proliferating cell nuclear antigen (PCNA) and recurrence in a population of 30 meningioma patients. All of 6 patients (invasive meningioma) with brain invasion had a PCNA LI in excess of 5%. Recurrence was found in 4 of these patients. In 24 patients who did not have brain invasion, PCNA LI was 4% or less and only 1 case had recurrence. Recurrence occurred in 3 of 25 patients who underwent macroscopic total resection and all of these 3 cases had brain invasion and a PCNA LI in excess of 5%. The findings of this study indicated the existence of a close correlation between peripheral invasiveness of meningioma and its biological behavior.