Disseminated metastasis of neuroblastomatous component in immature mediastinal teratoma: a case report.

A 17-year-old man with high levels of serum AFP and hCG was diagnosed as having primary mediastinal GCT. Cisplatin-based chemotherapy decreased the biomarkers, but the mass showed further growth. Pathological examination of the resected mass revealed a mixture of immature and mature teratomas. Six months after the surgery, the patient died of a dissemination of neuroblastomatous cells, which were similar to those in the immature neural component of the primary tumor. A disseminated metastasis of neuroblastoma in immature mediastinal teratoma is a rare complication. Serum NSE can be a useful marker in detecting the metastasis.