Metastatic testicular choriocarcinoma and secondary hyperthyroidism: case report and review of the literature.

We report on a 16-year-old boy with metastatic testicular choriocarcinoma, increased levels of human chorionic gonadotropin and profound hyperthyroidism bordering on thyroid storm. Hyperthyroidism was secondary to elevated human chorionic gonadotropin, with a thyroid-stimulating hormone effect. Management consisted of suppressive therapy for the symptoms of thyrotoxicosis until chemotherapy achieved control of the primary tumor and elevated levels of human chorionic gonadotropin. Review of the urological literature demonstrated a lack of recognition of this potentially serious paraneoplastic syndrome and its management.