Bradshaw lecture, 1976. Thyroid medullary carcinoma.

The main characteristics of medullary carcinoma of the thyroid are its non-follicular histological appearance, resulting from its origin from the parafollicular C cells, its secretion of calcitonin, providing a relatively simple diagnostic test, and its equal sex incidence, in contrast to all other diseases of the thyroid. Sporadic cases are seen and it occurs in familial groups, with autosomal dominant inheritance, when it is associated with phaeochromocytoma and parathyroid hyperplasia to form the second type of multiple endocrine adenomatosis (MEA2). These last features make it necessary in every case of medullary carcinoma of the thyroid to examine other members of the family and to investigate the possibility of concomitant adrenal and parathyroid disease. The priorities of treatment when these are present and the indications for total thyroidectomy are discussed.