Image analysis of nuclear DNA content and morphometric characteristics of the tumor cells in human astrocytomas.

In order to estimate the degree of malignancy of astrocytomas, we applied image analysis to study the nuclear DNA content and morphometric parameters of individual tumor cells in surgically resected specimens of 20 patients. There were nine low grade astrocytomas (LGA) and 11 high grade astrocytomas (HGA). Although the mean DNA index did not indicate a significant difference between LGA and HGA, five (45%) of the 11 HGA had an aneuploid DNA distribution pattern. By contrast, all LGA had a diploid pattern. The ratio of the S-G2M phase (% S-G2M) of the HGA (17.5 +/- 12.3%) was significantly higher than that of the LGA (7.0 +/- 4.6%). From the morphometric analysis of the area and shape of the nucleus of tumor cells, we obtained quantitative estimates of the degree of nuclear pleomorphism in astrocytomas. The nuclei of the tumor cells of HGA had larger sizes, increased anisokaryosis and were more irregular. In contrast to flow cytometry, image analysis can be used for quantitative studies of morphological tumor cell characteristics of relevance in the grading of malignancy.