Fetal and neonatal germ cell tumors.

Germ cell tumors (GCTs) arise from the 'germline' - the primordial germ cells which are destined to become either the egg or the sperm. GCTs can be challenging to understand because their intrinsic pluripotency results in a wide spectrum of histologies and biologic behaviors. However, the histology of GCTs in the fetus and neonate is more restricted and the clinical spectrum more narrow than when these tumors occur later in life. GCTs in the fetus and neonate are predominately mature and immature teratomas, usually curable with surgery alone. And, given the efficacy of cisplatin-based regimens in GCTs, cure is likely even for those patients whose tumors contain the more malignant histologies, which in the neonate is usually yolk sac tumor. Recent advances in understanding the underlying aberrations in germline development continue to shed light on the genesis of these tumors and possible new avenues for treatment.