Timor-Tritsch IE, et al. - In this retrospective study, researchers appraised a new sonographic pattern to describe a novel, yet typical, microcystic pattern of papillary projections, solid components and/or septa as a new ultrasound marker of borderline ovarian tumors (BOTs) and present their histologic confirmation. Sixty-seven cases with pre-operative ultrasound that had a histologic diagnosis of BOT following surgical resection were included in the final analysis. The novel sonographic marker of BOTs termed “microcystic pattern” was identified in 60 (89.7%) of 67 BOTs in the papillary projections, solid components and/or septa. Majority of both the serous and the mucinous BOT cases displayed the microcystic pattern. Comparison of sonographic images and histopathology of both benign entities and malignancies suggest the microcystic appearance as unique to BOTs. No previous description of such or similar kind was observed. It seems that this new marker may assist in correctly recognizing BOTs, distinguishing them from ovarian cancers and benign ovarian pathologies, and ensure their appropriate clinical and surgical management.