KI-67 AND BIOLOGICAL BEHAVIOR IN MENINGEAL HEMANGIOPERICYTOMAS

The biological behaviour of meningeal haemangiopericytomas was retrosp ectively studied using immunohistochemical staining with MIB1, a monoc lonal antibody against the Ki-67 antigen, a nuclear protein related to cell proliferation. Paraffin-embedded material from 62 tumours from 4 0 patients were investigated. The proliferating compartment of the tum ours was estimated by evaluating the MIB1 staining index, i.e. the per centage of MIB1 positive nuclei in at least 1000 counted tumour cells in representative areas. The staining index ranged from 1.24% to 39.01 %. Statistical analysis revealed no significant correlation between th e staining index and recurrence-free survival (chi(2) = 0.3922, P = 0. 5311). Long-term observation (> 100 months), however, revealed a tende ncy to longer survival in the group with a staining index less than 5% . According to our results, the MIB1 staining index does not contribut e to the accuracy of predicting the clinical outcome of meningeal haem angiopericytomas.