immature ovarian teratoma (MONDO_0018369) is a malignant germ cell tumor arising from the ovary. It usually affects females in their first two decades of life. It contains variable amounts of immature embryonal tissues. Based on the amount of immature neuroepithelial component, immature teratomas are graded from 1 to 3. The stage and grade of the tumor and the grade of the metastatic tumor are the important factors that predict prognosis. The use of cisplatin-based combination chemotherapy has significantly improved the survival rates of the patients. Also known as: immature germ cell teratoma of ovary, immature germ cell teratoma of the ovary, immature teratoma of ovary, immature teratoma of the ovary, malignant germ cell teratoma of ovary, malignant germ cell teratoma of the ovary, malignant ovarian germ cell teratoma, malignant ovarian teratoma.