Flow cytometric analysis of the DNA distribution in human brain tumors

Flow cytofluorometric analysis was used to determine the distribution of the DNA content in cells from selected areas of normal human brain and in benign and malignant brain tumors. Propidium iodide was employed as DNA fluorochrome and the analysis was carried out on a suspension of single cells. Normal, nonstimulated human lymphocytes were used as diploid controls. With nonneoplastic tissue an average of 91% of the cells were diploid (presumably in G₀ or G₁ stage of the cell cycle). The cells of most benign tumors were mainly diploid (77-98%), nine specimens of pituitary adenomas had large numbers of aneuploid cells. In glioblastoma multiforme the proportion of diploid cells was significantly diminished and polyploid cells were frequently seen. Similar results were obtained in other malignant tumors, with metastatic tumors showing the greatest ploidy variation, which included triploid, tetraploid, and hypertetraploid cells. The analytical method used provides valuable information of significant clinical importance on the DNA distribution in brain tumor cells.