Malignant thyroid teratoma of an adult: a long-term survival after chemotherapy.

Adult primary malignant teratoma of the thyroid is a rare disease that has a poor outcome despite aggressive therapy. A 32-year-old woman underwent a simple lobectomy of the thyroid for a progressively enlarged nodule in August 1990. Pathologic assessment of the tumor revealed a malignant teratoma. The physical examinations and image studies failed to find tumor in other sites. She subsequently received 6 courses of chemotherapy with cisplatin, etoposide, and bleomycin. She experienced a complete response to chemotherapy and remained disease-free for 6.5 years. This tumor must be included in the differential diagnosis of a thyroid tumor and may be treated as a testicular germ-cell tumor for which chemotherapy may be recommended.