We report a patient with a vesicular thyroid carcinoma secreting somatostatin and associated to an endocrine duodenal calcitonin secreting tumour. Increase of plasm somatostatin level induced an endocrine syndrome which completely resolved after thyroidectomy. By contrast, the digestive tumour remained asymptomatic. Six months after surgery, the course was marked by a relapse of the thyroid tumour along with pulmonary metastasis. At that time, pathological analysis showed only indifferentiated tumoural tissue.