Intracranial dural metastasis of mediastinal seminoma--case report.

A 24-year-old male presented with a rare intracranial dural metastasis from a mediastinal germ cell tumor infiltrating the superior vena cava, pericardium, ascending aorta, and lung. Routine chest radiography incidentally revealed the abnormal mediastinum, which was partially resected after median sternotomy, followed by radiotherapy. One year after the radiotherapy, magnetic resonance imaging revealed a right parasagittal tumor mimicking a meningioma. Partial tumor removal was performed. Two cycles of chemotherapy with carboplatin and etoposide were then performed, and the residual tumor almost completely disappeared. The histological diagnosis of both the mediastinal and intracranial tumors was pure seminoma. Sections of metastatic tumor revealed several thick fibrous septa and numerous epithelioid granulomas infiltrated by plasma cells, intermingled between the clusters of tumor cells. Follow up of patients apparently in remission from mediastinal seminoma without evidence of advanced or recurrent disease at other sites is recommended.