borderline epithelial tumor of ovary (Monarch Disease Ontology id MONDO_0016093) is a low grade epithelial tumor arising from the ovary. It is characterized by an atypical proliferation of epithelial cells. There is no evidence of stromal invasion. Also known as: borderline epithelial neoplasm of ovary, borderline epithelial neoplasm of the ovary, borderline epithelial tumor of the ovary, borderline epithelial tumour of the ovary, borderline ovarian epithelial neoplasm, borderline ovarian epithelial tumor, borderline ovarian epithelial tumour, borderline ovarian surface epithelial-stromal tumor.