Gliosarcoma with bone infiltration and extracranial growth: case report and review of literature.

Gliosarcoma is a relatively rare and highly malignant brain tumor consisting of both a glioblastoma and a mesenchymal component. Because of the natural barrier of the dura mater, that prevents intra or extradural neoplasm dissemination, cases of penetration of the dura and cranium by gliosarcomas without previous surgery or radiation are very rarely reported. We report an unusual case of gliosarcoma that involved the temporal skull base and the dura without antecedent radiation or surgery, although the lesion traversed the dura without radiologic or gross interruption of the dura. Remarkable in our case is the initial integrity of cerebral parenchyma. Follow-up revealed a tumorous infiltration of the temporal lobe almost one year after initial diagnosis. Thus the origin of the gliosarcoma in our case seemed to be extradural in the temporal skull base. Furthermore, this report demonstrates that extensive multi-modality treatment might be effective in patients with gliosarcomas and poor prognostic factors, for example unmethylated MGMT status.