Ovarian Seromucinous Borderline Tumors Are Histologically Different from Mucinous Borderline Tumors

Aim: To examine the clinicopathological features of ovarian seromucinous borderline tumors (SMBTs) and compare them with those of mucinous borderline/atypical proliferative mucinous tumors (MB/APMTs). Patients and Methods: Patients with SMBT between 2014 and 2018 and those with MB/APMT between 1988 and 2018 who underwent surgery at our Institution were identified. Pathological review was conducted using the 2014 World Health Organization criteria. Clinical features were compared retrospectively between SMBT and MB/APMT. Results: In total, 11 (12.9%) patients with SMBT and 74 (87.1%) patients with MB/APMT were included in our study. The diagnosis of six patients with SMBT and 73 patients with MB/APMT was not revised on review. SMBT was diagnosed at a younger age (p=0.04), was of smaller size (p<0.01) and bilateral (p=0.03), coexisted with endometriosis (p<0.01), and more frequently recurred than MB/APMT (p=0.04). Conclusion: SMBT might be more aggressive than MB/APMT.