EXCEPT for meningiomas, which often infiltrate the dura mater and skull, 23,6s one of the most outstanding and wellestablished features of primary intraeranial tmnors is their tendency to remain concealed within the dural sac, inside the craniospinal bony cavity. 5,~2,81,73 This usually holds true even when a recurrence develops after operation or when a glioma spreads by way of the cerebrospinal fluid pathways, as occurs often with medulloblastomas, ~,s,9,~5,31 ependymomas, 24'52,5s,66 oligodendrogliomas, 47,4s and sometimes with sarcomatous involvement of the leptomeninges. 4,6Nevertheless, exceptions to this rule may occur and one of us 45 reported in 195~ a case of very vascularized primary sarcoma (angiosarcoma) of the cerebellum in a 4-year-old boy which was removed surgically. A course of deep roentgen-ray therapy totalling 9,000 r was given after the operation. A year and a half later, a growth had developed in the muscles of the neck. The tumor, 5X~X3 cm. in size, was removed and a full course of roentgen-ray treatment totalling 10,000 r was given immediately after the second operation. Microscopical sections demonstrated that it was a fibrosarcoma. Investigations carried out to detect neoplastic growth elsewhere in the body gave negative results and the patient, who now has been followed for over 8 years, still is in good health. Therefore, it seems that the cerebellar sarcoma was a primary one, and the growth outside the skull, a metastasis.Earlier than this, the same senior author saw a cerebral glioma in a young adult with a * Read at the meeting of the Society of British Neurological Surgeons, Edinburgh, June 1960.long-standing history. At operation some tumor was found underneath the galea, outside tlle skull. Unfortunately, this patient was operated upon shortly after the end of the Spanish Civil War, and the pathological specimens were lost. IIowever, microscopical description of the tissue found outside the bone, as well as that within the brain, supported the diagnosis of glioma.In reviewing the literature we have been able to collect 81 cases of primary intracranial tumors and 1 of the eauda equina that gave rise to metastasis outside the cerebrospinal cavity.As always happens when surveying the literature covering a long span of time , there are some cases in which the histopathological identification of the lesions is difficult to establish because of insufficient data, as in the case reported by Lindner 46 under the diagnosis of "dural endothelioma" with metastasis in the urinary bladder; 1 published by Davis 25 of "spongioblastoma" of the left temporal lobe with metastasis in the right arm, lymph glands of the axilla, wall of the chest and lung, and 1 of "glioblastoma" with pulmonary metastasis reported by Mittelbach. 54 Lindner's case, as pointed out by many authors, could have been one of urinary carcinoma with metastasis to the brain and the other ~, as stated by Willis, 72 puhnonary carcinomas with cerebral metastasis.In other instances there may have been merely a co-existence of two ...
