Medullary carcinoma of the thyroid gland.

Endocrine as well as oncologic attributes mark this rare tumor as unique. It is derived from "C cells" resembling the parafollicular cells of lower animals; these cells elaborate Calcitonin which acts as a sensitive signal of the presence of the tumor. Other endocrinopathies are present in 70 percent of cases so that the tumor may present as part of a complex but increasing well known clinical picture. In 10 percent the tumor occurs as an autosomal dominant trait; in the remainder, the occurrence is sporadic. As expected the lesions are "cold" on I131 scan. The histologic appearance of amyloid is characteristic. Regional lymph node metastasis occurs early. The tumor deserves appropriate aggressive management. Essentially surgical therapy should begin early and vigorously; the minimum procedure should be total thyroidectomy. Frequent lymph node metastasis speaks for the need for radical neck dissection which should be extended into the superior mediastinum. Management should also include the frequently associated endocrinopathies, particularly pheochromocytomas which must be suspected and eradicted prior to treatment of the thyroid tumor. A genetic workup should be included. Six cases are described, ranging in age from the third to the eighth decade. Only two were free of disease at this writing, two were alive with their disease and two were dead of their disease. All were of the sporadic group, and only one had associated endocrinopathies. None of these cases were diagnosed preoperatively.