Sarcoma was once thought to be a common form of brain tumor. With improved methods of identification of these lesions opinion in this regard has changed, and of late this diagnosis is rarely made, except in the case of so-called sarcomatosis of the meninges. But even this condition proves to be really an invasion of the meninges by a round cell tumor of spongioblastic glial origin (called in this clinic medulloblastoma) so that these lesions as well are properly excluded from the sarcoma group.
A true sarcoma of the brain thus becomes exceedingly rare. During the course of a recent reexamination, by modern histologic methods, of about 400 brain tumors which had previously been diagnosed as gliomas, there were found only a few cases which could properly justify the designation of sarcoma. I have made a detailed investigation of these few tumors. Among them is one which has shown such
FRIED BM. SARCOMATOSIS OF THE BRAIN. Arch NeurPsych. 1926;15(2):205–217. doi:10.1001/archneurpsyc.1926.02200200056004