Poor outcomes in patients with primary malignant mediastinal germ-cell tumors.

Primary mediastinal germ-cell tumors (GCTs) without gonadal involvement are rare and can be divided into benign mature teratoma and malignant seminoma or nonseminoma. We describe our experience of malignant mediastinal GCTs and compare the presentations and outcome with those of benign teratomas. Four malignant GCTs (1 seminoma, 1 choriocarcinoma, and 2 yolk-sac tumors) have been treated in our hospital. All patients were men with obvious symptoms before diagnosis. The patient with seminoma was treated with surgery and radiation, while those with nonseminoma tumors were treated with chemotherapy and/or surgery. Two patients died, one with extended pulmonary metastasis and the other with relapsed disease and high levels of tumor markers. Compared with the nine cases of benign teratomas, the four malignant GCTs showed overwhelming male dominance, advanced symptoms at presentation, and poor outcome. These cases highlight the important role of disease staging and tumor-marker levels in malignant GCTs, and suggest that new treatment strategies for malignant GCTs await further investigation.