[Medullary cancer of the thyroid and multiple endocrine neoplastic syndromes].

Despite its rarity, medullary thyroid carcinoma which is hereditary in a quarter of cases and often associated with multiple endocrine neoplasia 2a and 2b syndromes, avises much interest which has lead to the formation of a French multidisciplinary group for the study of calcitonin tumors. This collaboration has resulted in the establishment of a national register and has broadened the knowledge of all specialists concerned. Consequently diagnostic methods are improved, becoming quicker, more reliable and also more thorough due to the setting up of therapeutic protocols. An immunocytochemical staining for calcitonin allows a preoperative diagnosis, providing optimal therapeutic conditions for the patients, especially systematic research of pheochromocytoma and management by a specialized team. Total thyroidectomy and careful lymph node dissection are recommended for all cases. Such progress significantly modifies the prognosis of the disease. Family screening, using plasma calcitonin and, in the near future, genetic studies will hopefully enable the identification of abnormal gene carriers before the clinical stage, thus making total recovery possible.