A New Insight on Exophytic Serous Borderline Adnexal Tumors: Specific Sonographic Features.

Objectives: To characterize and compare the sonographic features of exophytic serous borderline ovarian tumors (ESBOT) with those of high-grade serous carcinoma of the ovary (HGSC).

Methods: Seven patients with histological diagnosis of ESBOT diagnosed between 2011 and 2019 and 10 consecutive cases of HGSC detected during 2019, both depicting an exophytic growth pattern, were identified retrospectively. The sonographic imaging of the masses was reassessed and characterized according to the International Ovarian Tumor Analysis terms.

Results: A unilateral irregular solid adnexal mass was demonstrated in all patients with ESBOT. The mass typically wrapped an apparently normal ovary, with a clear demarcation line depicted between them and it contained tiny cystic inclusions and calcifications. On color Doppler study of all the ESBOT cases, a unique vascular pattern could be demonstrated: an intratumoral vascular bundle originating from the ovarian vessels and supplying a rich radial blood flow to the tumor periphery. These characteristic morphological and color Doppler features could not be observed in any of the HGSC cases (P < .001). In 42.8% of the patients with ESBOT, additional unilocular-solid components (ipsilateral or contralateral) could be detected, whereas all the HGSC patients presented with a multilocular-solid tumor morphology (P < .001). The interface of the external mass border with the adjacent pelvic walls was regular in all the cases with ESBOT, whereas in 80% of HGSC patients, it was irregular, suggesting invasiveness (P = .002).

Conclusions: ESBOT can mimic HGSC. Our results suggest that ESBOT has specific B-mode and color Doppler features, enabling differentiation from HGSC and planning appropriate intervention.