DNA ploidy analysis of borderline epithelial ovarian tumours.

OBJECTIVE Borderline epithelial ovarian tumours not uncommonly pose a great difficulty to surgical pathologists as morphologically they may show very similar features as those of malignant epithelial tumours except invasion. However it is important to separate these from their invasive counterparts because of their superior prognosis. Recently, attention has been focussed on the prognostic value of flow cytometric analysis of DNA ploidy in borderline epithelial ovarian tumours. The purpose of this study is to investigate whether flow cytometric analysis of cellular DNA content acts as a useful adjunct to the histopathological diagnosis of borderline malignancy. MATERIALS AND METHODS Fifteen histologically confirmed borderline serous epithelial tumours of the ovary were selected. Samples were analyzed on a FACScan flow cytometer using the software MODFIT. A total of 10,000 nuclei were counted each time. RESULTS The mean CV for the 15 cases was 3.67 (Range 2.4-5.0). In the DNA histograms a diploid sample was defined as one that had a single Go/Gl peak. An aneuploid tumour was defined as one that displayed an additional distinct peak. All 15 cases of borderline serous epithelial tumours showed a diploid stemline with DNA index between 0.9-1.10. CONCLUSION This study suggests that aneuploidy if ever demonstrated in histologically confirmed borderline tumours should prompt extensive sampling of the tumour and a close follow up.