Necrosis and apoptosis of tumor cells in embolized meningiomas: histopathology and P53, BCL-2, CD-68 immunohistochemistry.

The preoperative embolization of intracranial meningiomas, used in selected patients to reduce tumor vascularity and blood loss during surgery, may produce ischemic changes and/or tumor necrosis. The aim of the present study was to determine the relationship between necrosis within the embolized tumors and expression of two apoptosis-associated proteins (p53 and bcl-2) and macrophage-monocyte CD-68 antigen. Four biopsy specimens of embolized meningiomas, including three benign and one atypical tumor, were revived histopathologically and examined immunohistochemically using the monoclonal antibodies to p53, bcl-2 proteins and CD-68 antigen. The observations showed that the p53-immunopositive cells were most frequent in perinecrotic and ischemic areas than in non-ischemic, intact parts of tumors. The bcl-2 protein was expressed predominantly in well-preserved regions lacking ischemic tumor cells, whereas in close proximity to the necrosis only a few bcl-2 positive cells could be detected. Anti-CD-68 immunostained cells were distributed around or within the necrotic foci. Our results indicate that the expression of apoptosis-related proteins correlates with ischemic cell injury induced by preoperative tumor embolization.