[Primary malignant teratoma of the thyroid. Report of one case and review of the literature (author's transl)].

Malignant teratomas of the thyroid in the adult are rare. A personal case is presented. It brings the total number of cases found in the literature to nine, and illustrates the terrible prognosis of these tumours regardless of the treatment used (extensive surgery, radiotherapy, chemotherapy). Teratomas in the adult thus differ from those in the newborn and child. The latter are much more common and recurrences virtually non-existent. The histogenesis of these tumour is discussed. It may dysgenetic heterotypism, but no definite conclusions may be offered.