Objective The borderline ovarian Brenner tumor (BOBT) of the ovary is a rare tumor, and fewer than 25 cases have been reported in the literature. The aim of this study was to determine the prognosis of a series of BOBT collected in 2 reference centers.

Methods A retrospective review of patients with BOBT treated or referred to our institutions. A centralized histological review by a reference pathologist and data on the clinical characteristics, management, and outcomes of patients were required for inclusion.

Results Ten patients were identified between 2000 and 2010. The median age of patients was 69 years (range, 52–84 years). Eight patients had pure BOBT and 2 had mixed histotype (mucinous and Brenner tumor). All patients had unilateral tumor and a stage I disease. No case of stromal microinvasion or intraepithelial carcinoma was observed. Among 5 patients with data on the follow-up, 1 lethal recurrence (50 months after initial surgery) was observed (the first reported in the literature).

Conclusions During the management of BOBT, peritoneal staging surgery is not required because all patients reported in the present series (and all but one in the literature) had stage I disease. One recurrence had occurred in this retrospective series. Nevertheless, among 35 cases (including those in the present study) reported in the literature with outcomes, this tumor carries a good prognosis. The power of this conclusion is, however, limited because of the relatively small number of patients studied (but this is a rare entity) and the short follow-up period.