A laboratory finding of alpha-fetoprotein or human chorionic gonadotropin would suggest that the tumor is mixed. Primary germ cell tumors of the mediastinum are also associated with Klinefelter syndrome and hematologic malignancies. These patients have nonseminomatous tumors and tend to present at a younger age than those without Klinefelter s. The association of nonseminomatous germ cell tumors and hematologic malignancies has been confirmed by several studies. Acute leukemias, myelodysplastic syndrome, malignant histiocytosis and thrombocytopenia have been reported in patients with malignant germ cell tumors.
Resection is usually curative for mature teratoma.
Resection, chemotherapy and radiation have dramatically improved the prognosis for malignant germ cell neoplasms. Hasle H, Jacobsen BB, Asschenfeldt P, Andersen K. Mediastinal germ cell tumour associated with Klinefelter syndrome. A report and review of the literature.