Flow-cytophotometry of nuclear DNA in biopsies of 45 human gliomas and after primary culture in vitro.

DNA distribution in biopsies and cell cultures of human gliomas was examined by flow-fluorescence-cytometry using ethidium bromide staining. Glioblastomas (n = 25) showed "polyploid", "marked tetraploid", or "hypertetraploid" aneuploid karyograms, comparable to subtypes previously proposed by Japanese authors. "Diploid-hyperdiploid" DNA patterns were manifest in 3 cases plus 1 sarcoma--glioblastoma, containing abundant rapidly growing mesenchymal cells. Most tumors showed S-phase increment. "Near-diploid" patterns could be a result of aggregated cells, and small 4 C peaks could be due to non-representative specimens (3 cases). During cultivation, the DNA distribution usually remained stable, but maxima occasionally shifted. Oligodendrogliomas (n = 11) and astrocytomas (n = 9) of low-grade showed low 4 c peaks. High-grade gliomas, however, showed abnormal DNA patterns. Thus, one case of an oligodendroglioma--I developed an abnormal "marked tetraploid" glioblastoma after a 3-year interval presenting its malignant transformation. DNA distribution can obviously vary during tumor evolution. However, it may well support the assessment of grading and more closely define the prognosis in gliomas.