borderline ovarian serous tumor (MONDO_0020662) is a low grade serous epithelial neoplasm arising from the ovary. It is characterized by an atypical proliferation of serous-type epithelial cells without evidence of stromal invasion. It is often asymptomatic but rarely it may present with abdominal pain or abdominal enlargement due to rupture or torsion. Also known as: borderline ovarian serous neoplasm, borderline serous neoplasm of ovary, borderline serous neoplasm of the ovary, borderline serous tumor of ovary, borderline serous tumor of the ovary, borderline serous tumour of ovary, borderline serous tumour of the ovary, ovarian serous neoplasm of low malignant potential.