[Medullary carcinoma of the thyroid (author's transl)].

Medullary carcinoma of the thyroid develops in the parafollicular C cells, the origin of which is in the neural crest. It is characterized clinically by the presence of motor diarrhea, vasomotor attacks, and immunologically by the presence of an amyloid stroma and the appearance of an anaplastic carcinoma. It is frequently associated with a pheochromocytoma (Sipple's syndrome), parathyroid adenomas and cytaneo mucosal manifestations (phacomatosis, multiple mucosal neuromas). The C cells may secrete thyrocalcitonin and the estimation of the substance may be sometimes used in pre-operative diagnosis and, above all, subsequent observation and examination for the presence of metastases. Treatment is based upon surgery (total thyroidectomy) with lymphnode dissection. Complementary treatment (radiotherapy, chemotherapy, opotherapy) is given only when surgery is inedequate or recurrences occur.