Ovarian serous borderline tumors with lymph node involvement. Clinicopathologic and DNA content study of seven cases and review of the literature.

Although several studies have established the excellent prognosis of ovarian serous borderline tumors (OSBTs) in general, the significance of lymph node involvement has not been thoroughly addressed. In this article, we describe seven OSBTs with lymph node involvement and their DNA content and S-phase fraction. Lymph node involvement was identified at presentation in four cases (pelvic, paraaortic, and omental) and after 4, 5, and 7 years in the other three (omental, scalene, and cervical, respectively). In the first group, clusters of cells cytologically similar to those of the OSBT were identified in the nodal sinusoids in all four cases and focally in the lymph node parenchyma in three of them. In contrast, the involved lymph nodes of the three cases with delayed nodal disease showed an almost complete replacement by tumor. In one of them, the tumor in the lymph node was histologically similar to the OSBT, while in the other two cases the tumor was more solid and poorly differentiated, suggesting true metastatic disease. Flow cytometric analysis of nuclear DNA content and S-phase fraction were performed on paraffin-embedded tissue of all of the primary OSBTs and of the involved lymph nodes in six cases; diploid DNA content and low S-phase fraction were seen in all cases. All patients were alive and free of disease 2-9 years after initial diagnosis. While the clinical significance of LN involvement in OSBT is still uncertain, DNA ploidy analysis seems to be unable to identify those cases at risk for tumor progression.