Malignant teratoma of the thyroid: aggressive chemoradiation therapy is required after surgery.

Malignant teratoma of the thyroid gland is exceedingly rare in adults. Many of the cases previously reported in the medical literature have fatal outcomes because of spread of tumor refractory to treatment. We report a case of primary malignant teratoma of the thyroid in a 37-year-old woman. She was treated successfully with a combination of surgery, postoperative cis-platinum-based chemotherapy and radiation therapy to the neck, with long-term follow-up (10 years). This case and the modern experience of combined modality therapy in extragonadal germ cell tumors of the thyroid and other sites illustrate that these tumors should be managed aggressively in order to achieve best results.