Abstract: 【Abstract】  Ovarian yolk sac tumour （OYST）, also called ovarian endodermal sinus tumour （ＯＥＳＴ） are rare and highly malignant tumours of utmost importance occurring in children and young adults. AFP and glypican-3 are characteristic immunohistochemical markers. Cisplatin-based chemotherapy has dramatically improved the prognosis of OYST. Fertility-sparing surgery seems a reasonable approach in initial treatment even for patients with advanced stage. Three courses of BEP （bleomycin, etoposide, cisplatin） is the current standard therapy and four courses is recommended in case of bulky residual disease after surgery. There is a rare situation of ovarian yolk sac tumour complicating pregnancy in which adjuvant chemotherapy must be given after laparotomy. It can increase the risk of fetal malformation and pregnant death during gestation period. It may have an influence on prognosis in the case that tumor tissue types, selection of chemotherapy regimens, staging, not satisfied with the residual, preoperative and postoperative level of serum AFP. On the other hand, the choice of operation method has little impact on the prognosis of patients. Minimal invasive technique, assisted reproductive technology and protection of ovarian function during chemotherapy can make benefit in patients with malignant ovarian germ cell tumours.

Key words:  Endodermal sinus tumor, Neoplasms, germ cell and embryonal, Ovariectomy, Antineoplastic combined chemotherapy protocols, alpha-fetoproteins