Background: Ovarian yolk sac tumor (YST) that is diagnosed during pregnancy is extremely rare.
Clinical case: A 22-year-old pregnant woman diagnosed with Stage IIIc YST at 17 weeks of gestation is presented. A 20-cm multilocular cystic tumor containing solid components with massive ascites was detected. Subsequently she underwent left salpingo-oophorectomy and cytoreductive surgery for peritoneal dissemination at 18 weeks of gestation, and the tumors were diagnosed as YST. After vaginal termination at 20 weeks of gestation, she received five cycles of combination therapy with bleomycin, etoposide, and cisplatin. There was no evidence of recurrence at 85 months after primary treatment.
Conclusion: Considering the rarity, treatment strategy for advanced-staged YST should be further investigated in international collaborative studies.