Extraneural metastasis of intracranial germinoma with syncytiotrophoblastic giant cells--case report.

A 14-year-old boy presented with an extraneural metastasis of germinoma with syncytiotrophoblastic giant cells (STGC). The tumor was located in the pineal area, suprasellar cistern, and frontal base, and associated with the slight elevation of the beta-human chorionic gonadotropin (HCG) serum level. Following radiation therapy, the tumor completely disappeared, and the beta-HCG level decreased to normal. Two years after the initial treatment, metastasis of the tumor to the left femur was observed without recurrence of the primary lesion. The biopsy specimen revealed germinoma, the diagnosis was germinoma with STGC because of the associated elevation of HCG level. The metastatic tumor was treated by chemotherapy with cisplatin and etoposide, and the tumor completely disappeared. With adjuvant chemotherapy, he has been recurrence-free for 3 years. Extraneural metastasis occurs more frequently from germinoma with STGC than germinoma. Aggressive chemotherapy combined with radiation therapy in the initial treatment might have to be tried to avoid metastasis from germinoma with STGC.