DNA flow cytometry of ovarian tumors with correlation to histopathology

Tissue samples from 49 women with seven benign and 42 malignant ovarian tumors were examined by means of DNA flow cytometry (FCM). The FCM data (DNA-ploidy and the number of S-phase fractions) were compared with the International Federation of Gynecology and Obstetrics (FIGO) stage, the histologic grade of differentiation and in some cases with the clinical outcome. The benign ovarian tumors were all diploid with a mean of 2.1% (+/- 1.66) S-phase fractions. Adenocarcinomas with the histologic grade 1 were diploid and had a mean of 2.1% (+/- 1.17) S-phase fractions. Grade 2 adenocarcinomas were aneuploid in eight of nine cases and revealed an increased proliferative activity (7.7% +/- 2.67 S-phase fractions). A high number of aneuploid cases (nine of 13) and an increased DNA synthesis were found in grade 3 adenocarcinomas (12.0% +/- 5.72 S-phase fractions). Four of six malignant nonepithelial tumors also had high numbers of S-phase fractions (9.7-14.5%). A significant correlation between the histologic grade and the DNA synthesis, FIGO stage, and DNA-ploidy was found. DNA-FCM may be used as an additional diagnostic tool supplementing routine histopathologic examination of ovarian tumors for better biological characterization, especially for those with uncertain grading, for grade 2 neoplasms, and for malignant nonepithelial tumors.