Ovarian torsion of mixed epithelial tumor misdiagnosed as a malignancy in postmenopausal woman

RATIONALE Adnexal torsion is 1 of the most common emergency gynecological disease. It is more often diagnosed in reproductive age, but rarely in postmenopausal women. The clinical symptoms of adnexal torsion are nonspecific in postmenopausal women. Epithelial ovarian tumors are common in adults, and the risk of malignancy increases with age, especially after menopause. So, it is difficult to diagnose adnexal torsion precisely compared with reproductive women, and most cases of adnexal torsion with postmenopausal women are diagnosed as a malignancy preoperatively. We report a case of ovarian torsion with mixed epithelial tumor misdiagnosed as a malignancy in postmenopausal woman. PATIENT CONCERNS A 65-year-old woman presented lower left abdominal pain, and there was slight abdominal distension, but no tenderness or rebound tenderness on abdominal palpation. DIAGNOSES Radiologic assessments showed a huge multiseptated cystic mass with solid portion in the left ovary, and malignancy was suspected. The test for serum tumor markers revealed normal levels of cancer antigen 125 (CA-125). INTERVENTIONS The patient underwent a laparotomy and there was torsion of the left ovary. We conducted frozen biopsy of left ovary for confirming malignancy before performing staging surgery. OUTCOMES The result of a frozen section biopsy confirmed a borderline Brenner tumor associated with a benign mucinous tumor. Subsequently, total hysterectomy and right salpingo-oophorectomy were performed. The operation was completed without addition procedures LESSONS:: Ovarian torsion is benign in most cases and malignancy is rare. Although very rare, ovarian torsion can occur in postmenopausal women, and it should be taken into consideration that the possibility of malignancy is low in postmenopausal women with normal CA-125 levels. Instead of performing staging surgery, it appears to be appropriate to carry out surgery based on the result of intraoperative frozen section biopsy so that we were able to avoid unnecessary surgical procedures.