A 37-year-old, Chinese woman, premenopausal, presented to gynecologic clinic with a complaint of abdominal bulge for 4 mo. Symptoms started 4 mo before presentation with abdominal bulge, without abdominal pain. She had a history of breast fibroma surgery 6 years ago. The patient denied any family history of malignant tumours. Physical examination revealed obvious abdominal distension, positive mobility voiced sounds, positive fluid wave tremor and weak bowel sounds. Besides, the vital signs were as follows: Body temperature, 37.2 °C; blood pressure, 122/83 mmHg; pulse, 102 beats per min; respiratory rate, 18 breaths per min. Furthermore, the right breast had old surgical scars. Gynecological examination: an irregular mass, with a diameter of 12 cm, was found on the right ovary; left ovary and uterus had no obvious abnormalities. Tumor marker carbohydrate antigen 199 was not elevated (33.87 U/mL, reference, 0-37), but CA 125 was 1492.23 U/mL (reference, 0-35). Besides, thyroid function tests were within normal limits: free triiodothyronine, 6.24 pmol/L (reference, 3.5-6.5); free thyroxine, 19.63 pmol/L (reference, 11.5-22.7); thyroid-stimulating hormone, 1.44 μIU/mL, (reference, 0.55-4.78). No abnormality was found in routine blood analyses. Ultrasonography showed a 12.8 cm × 8.0 cm right adnexal mass containing solid and cystic components with abundant vascularization and 2.8 cm × 2.1 cm solid left adnexal mass. Besides, there was a large amount of free peritoneal fluid and thickened greater omentum. Computed tomography (CT) scan of the chest, abdomen, and pelvis revealed right lung atelectasis with a large right pleural effusion, gross ascites, and a large complex cystic pelvic mass. Overall, the radiological findings were suspicious of ovarian cancer.