Clinicopathological study of malignant ovarian germ cell tumor

In treating malignant germ cell tumors clinicopathologically at Kurume University Hospital, for 18 years, the total number of patients was 112, including 25 yolk sac tumors (YST), 10 mixed form germ cell tumors (MF), 36 dysgerminomas (DYS), 26 immature teratomas (IT), 2 choriocarcinomas (CHO) and 13 dermoid cysts with malignant transformation (DCMT). The average age of patients in each group was 25.9 years for DCMT patients. When DCMT cases were excluded, ages was closely related to the age of menarche in each patient. The 5 year survival rate for each germ cell malignancy after the first operation was 31.6% for YST cases, 20.0% for MF, 76.7% for DYS, 60.0% for IT and 50.0% for DCMT cases. Despite currently used aggressive kinds of chemotherapy, the clinical stage still had a prognostic significance in all malignant germ cell tumors except dysgerminoma. Since histological maturation of the tumor tissue following treatment courses was observed in YST and IT cases, the possibility of a relationship between prognosis and the histogenetic process was shortly discussed.