DNA in meningioma tissues and explant cell cultures. A flow cytometric study with clinicopathological correlates.

Flow cytometry was performed on stored frozen tissues and explant cell cultures from 39 meningiomas using ethidium bromide and mithramycin in a selective staining technique for deoxyribonucleic acid (DNA). The ploidy index and percentage of cells in the G0/G1, S, and G2/M phases were calculated for each specimen. The results were compared with the age and sex of the patients; the site, the histological subtype, and mitotic rate of the neoplasms; and the estrogen- and progesterone-receptor levels assayed in cytosol-enriched supernatants from cryostat-cut sections. Sixteen neoplasms (41%) were aneuploid. These included two recurrent neoplasms, seven of the eight neoplasms from patients with multiple meningiomas, and three clinically aggressive neoplasms (one hemangiopericytic and two anaplastic meningiomas). Significant correlations were found between values for the ploidy index (r = 0.75, p less than 0.01), the percentage of S-phase cells (r = 0.82, p less than 0.01), and the percentage of G2/M-phase cells (r = 0.69, p less than 0.05) in vivo and in vitro. The results support the suggestion that flow cytometry for DNA in meningiomas may be of value in predicting the behavior of these neoplasms, and indicate that under controlled conditions explant cell cultures may provide a useful model for the proliferative characteristics of meningiomas in vivo.