[Medullary cancer of the thyroid].

Medullary thyroid cancer (MTC) is either of the sporadic or familial type, whether it be isolated or constitute part of a type II multiple endocrine neoplasia. Progress in the knowledge of the disease has recently been obtained in the following ways: the IRMA assay of mature calcitonin, the disease marker, has permitted earlier diagnosis of familial cases and recurrence; the locus assignment of the gene on chromosome 10 now enables a valid discrimination in certain families of gene carriers; collaborative clinical, biological, pathological, therapeutic and epidemiological research on a nation-wide scale has had a beneficial effect on patients, with improvement in diagnosis of the familial forms, in disease prognosis, in cancer detection at an infraclinical stage, and in the regrouping and distribution of families in France.