Cancer of the thyroid--explorations of clinical biology

A brief review of the cancers derived from the follicular thyroid epithelium and parafollicular cells (medullar cancer) is made. The contribution of clinical biology to the diagnosis has little significance in the case of thyroid cancer. On the other hand, the quantitative analysis of thyroglobulin is very important for the detection of recurrence in the course of the follow-up of a patient who has been treated by complete thyroidectomy. The biological markers of medullar cancer are most specific. The observation of pathological secretion of thyrocalcitonin is determining for the diagnosis of medullary carcinoma. It must lead to a parathyroid and medulloadrenal exploration as well as to systematic investigation of family history. These steps are essential for the diagnosis of the syndromes of multiple endocrine neoplasias types 2a and 2b.