Central Nervous System Germ Cell Tumors

Germ cells tumors most commonly affect children and adolescents, and occasionally arise in the central nervous system. Except for mature teratomas, they are all malignant. Pure germinomas are exquisitely sensitive to treatment and are highly curable with craniospinal radiation therapy. Surgery plays no role other than to establish the histologic diagnosis. Diagnostic confirmation includes normal levels of serum and cerebrospinal fluid alpha-fetoprotein and at most only minor elevations in beta human chorionic gonadotrophin (beta-hCG). Although it has become quite common to use chemotherapy to reduce the dose and field of radiation in the treatment of germinomas, longer follow-up in these patients is revealing a significant number of subarachnoid and ventricular recurrences. A recent follow-up study in patients treated for intracranial germinomas showed no significant difference in the psychosocial functioning of those treated with chemotherapy and radiation compared with those treated with chemotherapy alone, which raises further questions about the rationale for modifying a proven successful treatment. Malignant non-germinomatous germ cell tumors are much more resistant to treatment and difficult to cure. Surgical resection appears to have prognostic significance, although the predilection for midline structures makes complete resection difficult if not impossible at times. The best results have been obtained with platinum-based chemotherapy and full-dose craniospinal radiation therapy. Pure teratomas are not typically responsive to chemotherapy or radiation therapy and surgery is the only proven treatment modality.