Modal DNA content of human intracranial neoplasms studied by flow cytometry.

The relative DNA content in 56 human intracranial tumors was investigated by flow cytometry and correlated to their histological type. Tumors with a modal DNA content within the diploid value (2c) +/- 1/2c were divided from those with heteroploidy. Of the "benign non-neuroepithelial tumors," the meningiomas (five), neurilemomas (two), pituitary adenomas (three), and one hemangioblastoma had a unimodal diploid/near-diploid DNA content. The "malignant non-neuroepithelial tumors" were both heteroploid (two metastatic carcinomas) and diploid/near-diploid (three meningeal fibrosarcomas and one primary malignant lymphoma). Of the neuroepithelial tumors, the highly differentiated gliomas all had a diploid/near-diploid DNA mode except one recurrent oligodendroglioma. The majority of the poorly differentiated gliomas also presented near-diploid DNA modes. Heteroploidy of primary brain tumors was not correlated with a more malignant clinical/biological behavior in the individuals in this study.