[Studies of the cell kinetics of human malignant testicular tumors].

The cellular DNA-content of 75 malignant testicular germ-cell tumours was determined by flow cytometry. The results are: Aneuploidy is a certain tumour marker in 95% of germ-cell tumours. The DNA-indices range from 2 c (diploid) to 6 c with a modal value around 3 c. 23% of germ-cell tumours are multiclonal. The S-phase percentage is higher than those of the most other solid tumours investigated so far and is 25.5% in seminomas and 35% in non-seminomatous germ-cell tumours. Further investigations of a greater number of tissues will show the importance of DNA-contents measurement by flow cytometry for the prognosis of testicular tumours, representing an addition to histopathology.