Determination of DNA ploidy, nuclear size, and proliferative activity by means of the computer-assisted image analysis of Feulgen-stained nuclei in 68 soft tissue tumors of adults.

The diagnostic values of the ploidy level, the proliferative activity, and the nuclear size in a series of 68 soft tissue tumors of adults were determined by digital cell image analysis of Feulgen-stained nuclei from formalin-fixed, paraffin-embedded tissues. The DNA ploidy level was characterized by calculating the DNA index (DI) and the percentage of the diploid and polyploid cells, and by typing the DNA histogram. Proliferative activity assessments were a function of the determination of the proliferation index (PI), ie, the percentage of cells engaged in the S phase of the cell cycle (SPF value). The present series included 19 benign and 49 malignant soft tissue tumors. The results show that DNA aneuploidy, as assessed by both the DI and the DNA histogram type, cannot be used as a discriminatory parameter for distinguishing between benign and malignant soft tissue tumors. Indeed, some benign cases may be highly aneuploid, whereas some highly malignant soft tissue tumors may be definitely diploid. In contrast, the determination of the percentage of polyploid cell nuclei seems to be a useful parameter in distinguishing between benign and malignant cases. In fact, the benign soft tissue tumors showed a very significantly lower mean percentage value of polyploid cell nuclei than the malignant cases. The determination of the proliferative activity also discriminated significantly between the benign and the malignant cases, the former proliferating more slowly than the latter. Lastly, the determination of nuclear size made it possible to differentiate the primary malignant soft tissue tumors, whether recurrent or not, that were associated with metastasis from those free of metastasis.