This is the most common malignant germ cell tumor in the pediatric population. Yolk sac tumors arise in the infant testis, ovary, sacrococcygeal region, vagina, uterus, prostate, abdomen, liver, retroperitoneum, thorax and pineal/third ventricle. The tumor mimics the yolk sac of the embryo and produces alpha-fetoprotein (AFP). Treatment includes: surgical resection, radiation and chemotherapy. This tumor is very responsive to chemotherapy regimens that include cisplatinum. - 2002