DNA-fluorescence-cytometry and prognosis (grading) of meningiomas--a study of 104 surgically removed tumors.

A total of 104 meningiomas of various histological types were examined microscopically and with flow fluorescence cytometry using the EBR staining technique and either an ICP 11 or an ICP 22 (PHYWE). Also tissue culture cells of 72 tumors were studied for their DNA content. There was a variable DNA distribution, which allowed a grading of malignancy according to a 3 or 4 grade scale. Useful information on the nature of a meningioma and its proliferative activity can be obtained during the surgical treatment. A majority of meningiomas show slowly proliferative DNA patterns typical for benign tumors. More than one third of the meningiomas show an intermediate configuration, probably associated with more or less semi-benign proliferative activity. 5.8% of our cases showed primary malignant tumors--except meningosarcomas.