Primary Mediastinal Germ Cell Tumors

Primary mediastinal germ cell tumors are rare neoplasms, which account for only 1-3% of all germ cell tumors. If a young man presents with a mass in the antero-superior mediastinum, an extragonadal germ cell tumor should be taken into consideration, and serum tumor markers alpha-fetoprotein and human chorionic gonadotropin should be determined. An anterior median sternotomy frequently is necessary to establish the histological diagnosis, but radical surgical procedures to accomplish complete resection are not indicated. With cisplatin-based combination chemotherapy patients with pure mediastinal seminomas attain disease-free long-term survival in a similar proportion as patients with advanced testicular seminomas. Patients with mediastinal nonseminomatous germ cell tumors can achieve similar complete remission rates as patients with testicular nonseminomatous germ cell tumors with poor-prognosis metastatic disease; however, complete response of mediastinal tumors to chemotherapy alone is rare, and the majority of patients requires adjunctive surgery. Prognosis of mediastinal nonseminomatous germ cell tumors is somewhat impaired by an association with hematologic malignancies and by the occurrence of sarcomatous components. Although advances in the treatment of mediastinal and testicular germ cell tumors have closely paralleled, mediastinal germ cell tumors constitute a unique entity and require specialized management.