DNA flow cytometry in the prognosis of primary malignant melanoma.

DNA flow cytometry was carried out on 804 primary melanomas. The data were analyzed with a follow-up of 24-96 months. 57% of the cases were diploid, 32% had one abnormal cell population, and 11% were multiclonal. In 8% of the aneuploid tumors there were cell lines in the hypertetraploid range. A reliable S phase determination was possible in 524 cases. Among these 11% had an S phase exceeding 15%. Using an increased tumor thickness, relapse rate and mortality as criteria of tumor progression, aneuploidy and multiclonality, the occurrence of hypertetraploid cell lines and a high S phase (greater than 15%) proved to be correlated with a poor prognosis.