Intracranial Germinoma
Intracranial germinoma occurs in 0.7 per million children. As with other germ cell tumors (GCTs) occurring outside the gonads, the most common location of intracranial germinoma is on or near the midline, often in the pineal or suprasellar areas; in 5-10% of patients with germinoma in either area, the tumor is in both areas. Like other (GCTs), germinomas can occur in other areas of the brain. Within the brain, this tumor is most common in the hypothalamic or hypophyseal regions. In the thalamus and basal ganglia, germinoma is the most common GCT.
The diagnosis of an intracranial germinoma usually is based on biopsy, because the features on neuroimaging are similar to other tumors.
Cytology of the CSF often is studied to detect metastasis into the spine. This is important for staging and radiotherapy planning.
Intracranial germinomas have a reported 90% survival to five years after diagnosis. Near total resection does not seem to influence the cure rate, so gross total resection is not necessary and can increase the risk of complications from surgery. The best results have been reported from craniospinal radiation with local tumor boost of greater than 4,000 cGy.