Imaging in gynecological disease: clinical and ultrasound features of mucinous ovarian tumors.

OBJECTIVES: To describe clinical and ultrasound findings of mucinous ovarian tumors.

METHODS: Patients with a histological diagnosis of mucinous ovarian tumor who had undergone preoperative ultrasound examination were retrospectively identified from a single ultrasound center. The histological examination was performed by the same pathologist in all cases. The masses were described using the terms and definitions of the International Ovarian Tumor Analysis group.

RESULTS: We identified 57 (46%) women with a benign cystadenoma, 34 (28%) with a gastrointestinal (GI)-type borderline, 10 (8%) with an endocervical-type borderline and 22 (18%) with a GI-type invasive carcinoma. On ultrasound examination, 65% (37/57) of cystadenomas were multilocular cysts with few locules (≤10) in 22/37 (59%) cases; 79% (27/34) of GI-type borderline tumors were multilocular cysts with more than 10 locules in 24/27 (89%) cases. Conversely, 60% (6/10) of endocervical-type borderlines were cysts with papillations. 82% (18/22) of invasive masses contained solid components and 55% (12/22) of the invasive masses were multilocular-solid cysts. Bilateral mucinous cystadenomas were found in two women (2/57; 4% of women with benign tumors) and bilateral borderline tumors of endocervical type in two women (2/10; 20% of women with borderline tumor of endocervical type). No woman had a bilateral GI-type borderline tumor (0/34 women) or a bilateral invasive tumor (0/22 women).

CONCLUSIONS: A multilocular cyst with 2-10 locules is a representative image of a benign cystadenoma whereas a multilocular cyst with > 10 locules is indicative of a GI-type borderline tumor. Most invasive tumors of mucinous GI type contain solid components, the most typical ultrasound appearance being that of a multilocular solid tumor. Papillary projections are typical features of endocervical-type borderlines.