STUDY OF THE DNA CONTENT BY FLOW-CYTOMETRY AND PROLIFERATION IN 281 BRAIN-TUMORS

In this paper we investigate the distribution of DNA ploidy as well as proliferation rate (S phase of the cell cycle Ki-67 staining) in 281 tumors of the central and peripheral nervous system (87 meningiomas, 7 5 astrocytomas, 44 nerve sheath tumors, 25 brain metastases, 18 pituit ary adenomas, 17 ependymomas, 12 oligodendrogliomas and 3 medulloblast omas) and their correlation with the histopathological grade. Consider ing all 281 tumors, aneuploidy is the most frequent finding present: 5 2%. This percentage increases with malignancy: 69% of malignant tumors are aneuploidy. Levels of aneuploidy decrease from brain metastases t o pituitary adenoma (92% in brain metastases, 83% in oligodendroglioma s, 59% in nerve sheath tumors, 47% in ependymomas, 40% in astrocytomas , 35% in meningiomas and 33% in pituitary adenomas), but aneuploidy is also found in many benign tumors. With respect to proliferation rate of tumors, S phase above 20% were recorded in the more malignant tumor s: brain metastases, oligodendrogliomas, high-grade ependymomas, high grade astrocytomas, and in atypical and malignant meningiomas, but thi s parameter is not able to distinguish between low and high grade tumo rs. However, Ki-67 reactivity was equivalent in all histologies with s ignificant differences between low and high grade tumors.