[Thyroid metastases of digestive carcinomas (author's transl)].

The authors report a case of thyroid metastasis of a rectal carcinoma 9 years after excision of the primary tumour. They study the prevalence of thyroid secondary localisations of the chief primary tumours responsible, the time before appearance of the metastasis, and clinical and histological features on the basis of cases reported in the literature. They then describe the pathogenic factors and criteria in prognosis which is always grave, as a result of the dissemination of metastases.