Malignant primary meningeal tumors.

1) Out of 160 primary meningeal tumors surgically treated, 10 cases had histologically malignant tumors. Of them two cases of sarcoma and one case of meningioma with marked invasiveness were filed in malignant (sarcoma) group, and six cases of angioblastic meningioma of hemangiopericytoma type and one case of meningioma with partial invasiveness in semi malignant group. 2) Average duration of symptoms before admission was 3.2 months in the malignant group, 13.6 months in the semimalignant group and 28.5 months in the benign meningioma group. Incidences of papilledema was seen in 80% of the malignant and semi malignant groups and 58.5 % in the benign meningioma group. 3) Plain skull X-ray films did not reveal a marked osteoplastic change of the skull related to the tumor in the malignant and semi malignant groups. Lytic or destructive changes of the skull at the tumor site were noted in two cases. 4) An angiographic characteristic of meningeal tumors with malignancy was in most cases a marked blood supply from the intracerebral arteries into the tumor. 5) Of nine cases of postoperative survivals, recurrence occurred in three cases and probable recurrence in one other case, all of which were of angioblastic meningioma. 6) Irradiation resulted in some clinical improvements in two cases of angioblastic meningioma, but it was not curative after all. 7) Complete surgical excision was the best method for the prognosis of meningeal tumors with malignancy. If neuroradiological findings suggest a meningeal tumor with malignancy, surgical tactics should be radical in its true sense.