Objectives: To report an extremely rare case of ovarian borderline mucinous cystic tumor accompanied by low-grade endometrial stromal sarcoma (LGESS) with myxoid change.
Case presentation: A 42-year-old woman complained of lower left abdominal fullness. Her serum carcinoembryonic antigen, cancer antigen (CA) 125, and CA19-9 levels were normal. Magnetic resonance imaging showed a 10-cm cystic mass with a 5-cm nodule in its wall, and a laparoscopy indicated a cystic mass at the left adnexa. Histology indicated a cystic lesion consisting of proliferative gastrointestinal-type epithelium; the mural nodule had a characteristic of striking myxoid change, preservation of arteriolar pattern, and a "tongue-like" infiltration.
Conclusions: The diagnosis of ovarian mucinous borderline tumor accompanied by LGESS with myxoid change was appropriate.
Keywords: LGESS; Mucinous borderline tumor; Mural nodules; Myxoid change.