Objectives Staging procedure in borderline ovarian tumors is a topic of controversy. Upstaging in non-serous borderline ovarian tumors that are confined to the ovary is rare. The aim of this study was to assess the impact of surgical staging on clinical outcomes in mucinous borderline ovarian tumors.

Methods This was a retrospective study conducted at the Asan Medical Center, Seoul, Korea between January 1990 and December 2015, that included 432 patients with mucinous borderline ovarian tumors and at least 6 months follow-up. These patients were divided into a ‘staging group’ and ‘unstaged group’. The staging group referred to patients who, in addition to hysterectomy and/or adnexal surgery, underwent at least one of the following: cytology, omental biopsy/omentectomy, peritoneal biopsy, lymph node biopsy/lymphadenectomy, or appendectomy. The unstaged group referred to patients who did not undergo any staging procedure but underwent adnexal surgery (cystectomy or oophorectomy).

Results Median patient age was 40 (range 9–87) years. A total of 367 patients (85%) underwent a staging procedure (staging group) and 65 (15.0%) patients did not (unstaged group). Among the staging group, 258, 4, 100, and 5 patients were FIGO stage IA, IB, IC, or II-III, respectively. Overall recurrence was confirmed in 15 patients and median time to recurrence was 13.4 (range 0.4–127.3) months. One patient was in the unstaged group and had borderline recurrence. Fourteen were in the staging group, and 11 of them had borderline and three had invasive recurrence. Extraovarian disease was found at recurrence only in two patients. There was no significant difference in recurrence-free survival (p=0.39) and in overall survival between the staging group and the unstaged group (p=0.40). In total, 16 (4.4%) of 367 patients who underwent a staging procedure were upstaged.

Conclusion Staging in mucinous borderline ovarian tumors may be omitted if there is no obvious evidence of gross extraovarian disease.