Astrocytoma arising in meningeal fibrosarcoma

The authors describe a rare case of mixed glioma-sarcoma arising in primary meningeal fibrosarcoma as described by Rubinstein, in contrast to the more familiar mechanism of sarcoma arising from hyperplastic blood vessels in primary glioblastoma as described by Feigin. The two interpretations are by no means mutually exclusive, as both have been documented with a higher proportion of such mixed glioma-sarcomas being of the Feigin type. There exist, therefore, dual pathways in the histogenesis of mixed glioma-sarcoma, both of which are sufficiently well documented as to justify resurrection of the historical term "gliosarcoma", in accordance with the rigid criteria stipulated for diagnosis of this truly biphasic CNS tumor.