Mixed tumors contain elements of more than one of the above classes of tumor histology. To be classed as a mixed tumor, the minor type must make up more than 10% of the tumor. Though mixed carcinomas can have any combination of cell types, mixed ovarian cancers are typically serous/endometrioid or clear cell/endometrioid. Mixed germ cell tumors make up approximately 25–30% of all germ cell ovarian cancers, with combinations of dysgerminoma, yolk sac tumor, and/or immature teratoma. The prognosis and treatment vary based on the component cell types.