[Cytophotometric investigations of the nuclear DNA content in ependymomas and plexuspapillomas (author's transl)].

Report on Feulgen-cytophotometric DNA investigations in 10 ependymomas and 2 plexuspapillomas. All ependymomas represent in their karyograms aneuploidic stem lines. In most of them one observes duplication peaks (G2 cells) as expression of proliferation behaviour. The histological benign ependymomas exhibit stem lines between the hyperdiploid and hypotetraploid values. With increasing malignancy the stem lines are elevated in higher ploidy levels and a reduction of a predominant stem line is recognizable. One of the ependymomas represents a distribution of DNA values like in a "mosaic" tumour. The measurements in the plexuspapillomas in good conformity with the histologic picture reflect the DNA distribution of a benign euploid neoplasm.