Germ Cell Tumors

Intracranial germ cell tumors (IGCTs) are rare and are most common in childhood. These tumors most often occur in the pineal gland or suprasellar region. Overall, there is a male predominance, which is more pronounced for pineal gland tumors. In the past, these tumors were thought to be more common in East Asia, but more recent studies of larger databases suggest that the incidence is very similar in the United States and Japan. There are two groups, germinomas and nongerminomatous germ cell tumors. Histological subtype is an important factor for the stratification of prognosis and treatment. Recent molecular studies are shedding light on genes that may be involved in tumorigenesis. Germinomas are more common and can be cured with radiation therapy alone. For localized disease, fields have decreased in volume from craniospinal irradiation to whole brain or whole ventricular fields. Further reduction to focal irradiation fields has resulted in an increase of intraventricular failure. Combining chemotherapy with radiotherapy has permitted further decreases in radiation dose. Chemotherapy only strategies that omit irradiation have not been proven to be satisfactory. Nongerminomatous germ cell tumors have a poorer prognosis, and best results have been achieved with chemotherapy and craniospinal irradiation. The most recent Children’s Oncology Group trial has been studying smaller volumes and lower doses for those patients who respond well to neoadjuvant chemotherapy. Long-term survivors may have changes in quality of life, neurocognition, and endocrine function. There is no standard of care for recurrent germ cell tumors though high-dose chemotherapy and reirradiation may play a role.