Primary malignant teratoma of the thyroid: case report and literature review of cervical teratomas in adults.

A case of primary malignant teratoma of the thyroid in a gravid 37-year-old female is reported and the literature on cervical teratomas in adults reviewed. The patient was treated by total thyroidectomy and left radical neck dissection followed by cervical and mediastinal radiotherapy and chemotherapy. She fied of recurrent tumor and related complications 9 months after discovery of the lesion. This is the 6th case of primary teratoma of the thyroid and the 9th case of cervical teratoma reported in a adult. These tumors are characteristically large, rapidly growing and highly malignant. The longest survival reported is 10 months. The differentiation of this lesion from carcinosarcomas of the thyroid is discussed.