Serous borderline tumors of the ovary.
The distinction of borderline tumors from invasive carcinomas is one of the commonest problems in ovarian tumor pathology. The borderline tumors are characterized by absence of destructive stromal invasion although they can implant on peritoneal surfaces. The implants may in turn invade the underlying tissue. Serous borderline tumors (SBTs) account for one-quarter to one-third of malignant serous tumors. Mostly, they are confined to the ovary (Stage 1), whereas in some cases they spread within the pelvis (Stage 2) or upper abdomen (Stage 3). As recently shown, typical SBTs may contain foci of microinvasion, a finding that does not appear to influence the prognosis. SBTs are associated with peritoneal implants in about 30% of cases. Peritoneal implants most often appear similar to the primary ovarian tumor, although they could show more or less atypia than the primary tumor. The peritoneal implants of SBTs have been classified into non-invasive and invasive categories. Recently, some studies showed that in SBTs associated with peritoneal implants, separation of the implants into invasive and non-invasive categories has important prognostic implications. Furthermore, severe nuclear atypia and mitotic activity in the implants are independently related with a poor prognosis. In addition, these studies suggest that chemotherapy is appropriate only for patients with invasive implants without taking into account lymph node status. Finally, it has recently been established that tumors with a morphology identical to that of SBTs may arise as primary tumors of the peritoneum with absent or minimal involvement of ovarian surfaces.
Prat
J
Department of Pathology, Autonomous University of Barcelona, Barcelona, 08025, Spain.