RESUMO
Yolk sac tumours of the ovary are rare and highly malignant germ cell tumours, which comprise of only 10%-15% of all malignant germ cell tumours. They have various clinical presentations most common being subacute pelvic pain and feeling of lump but sometimes high-grade fever can be one of the rare presentations. Here, we present a case report of a 26-year-old nulliparous woman with 36 weeks gravid uterus size advanced stage yolk sac tumour of one ovary with fever as main clinical presentation and overt hypothyroidism. We did staging laparotomy with total abdominal hysterectomy with bilateral salpingo-oophorectomy and omentectomy with multiple peritoneal biopsies. Postoperatively, we had started adjuvant chemotherapy. Since yolk sac tumours are highly aggressive tumours as they rapidly increase in size, their early diagnosis and appropriate surgical management is required particularly in young women where fertility sparing surgery is possible in early stage with good prognosis.