Biologic heterogeneity of angiomatous meningiomas

Three angiomatous meningiomas, classified histologically as benign, were analyzed cytogenetically and examined for the expression of EGF/PDGF and their receptors by immunohistochemistry. An accumulation of p53 protein and the presence of mutations in exons 5-8 of the p53 gene in neoplastic cells were also determined. In one tumour, chromosome studies revealed near diploid karyotype with the loss of chromosome 22. Two other meningiomas revealed tetraploid karyotypes with the presence of telomeric associations and a wide spectrum of numerical, complex chromosome aberrations. Moderate EGF and EGFR immunoreactivity was found in three and one meningioma, respectively. All tumours exhibited diffuse PDGF and PDGFR-beta expression. No p53 gene mutations were found, but one tumour expressed strong and dispersed p53 immunopositivity. This findings reflect the biological heterogeneity of angiomatous meningiomas.