No abstract

No abstract

To detect familial medullary thyroid carcinoma in a premetastatic stage, we administered tests provocative of calcitonin secretion (infusion of calcium or pentagastrin or both) each year for seven years to members of a pedigree now numbering 107. Since 1970, 21 patients converted from normal to abnormal secretory responses (two separate tests in which calcitonin levels exceeded 0.58 ng per milliliter). Twenty of 21 glands removed showed C-cell hyperplasia, and eight of the 20 also showed foci of carcinoma. As compared to the 12 patients with tumors detected during the first year of screening, all of whom had bilateral carcinoma (seven of 12 with local metastases), later carcinomas were smaller (mean diameter of 0.2 vs. 0.8 cm), were unilateral (in all but two cases) and occurred in younger patients (mean age of 14.9 vs. 36.4 years), and none had detectable metastases.

The association of medullary carcinoma of the thyroid with pheochromocytoma and other neuroectodermal tumors constitutes a now well-recognized clinical syndrome.1-6 In several cases', 7-10 adenomas or hyperplasia of the parathyroid glands has been noted. Williams11 has presented evidence to suggest that the tumors in the thyroid gland may arise from parafollicular cells, which in most mammals are considered to be the source of thyrocalcitonin,12-14 a hormone which lowers plasma calcium by inhibiting bone resorption.15No syndrome in man resulting from hypersecretion of thyrocalcitonin has yet been documented conclusively. Two cases of so-called "calcitonin-excess syndrome" have been reported,16 17 but hypocalcemia improved only briefly after total thyroidectomy.The present case is the first documented example of a thyrocalcitonin-secreting tumor and of hypocalcemia with secondary hyperparathyroidism resulting from increased levels of circulating thyrocalcitonin.Clinical Details.-Case report: A 32-year-old white male presented with a clinical picture typical of pheochromocytoma. Eleven years previously he had undergone subtotal thyroidectomy for carcinoma of the thyroid. Histological sections from that operation showed medullary carcinoma with abundant amyloid and calcification. Mild tetany postoperatively was readily controlled with calciferol and calcium supplements. These medications were stopped after 4 weeks without recurrence of tetany until 9 years later. The patient's mother had died in her thirties of thyroid cancer, and his sister underwent thyroidectomy at the age of 17 for "adenocarcinoma" of the thyroid, from which she died 4 years later.For 9 years after the thyroidectomy, the patient remained in excellent health. In 1965 he first developed diarrhea with occasional episodes of tetany. The symptoms were not sufficiently severe to interfere with his work as a dental technician. In February 1967, the diarrhea and tetany occurred more frequently and hypocalcemia was confirmed. Treatment was started with calciferol, 100,000 units daily; calcium lactate; and thyroid U.S.P., 120 mg daily. Thereafter he remained reasonably well until the onset of his lresent illness.On admission he appeared gravely ill, with a labile blood pressure, paroxysmal tachycardia, and episodes of profuse sweating and extreme pallor. Chvostek's and Trousseau's signs were strongly positive. A clinical diagnosis was made of familial medullary carcinoma of the thyroid with pheochromocytoma and hypocalcemia. Treatment with calciferol was increased to 200,000 units daily, and total elemental calcium supplements to 3.35 gm daily.Laboratory data showed: serum Ca 6.4 mg %, phosphate 3.0 mg %, alkaline phosphatase 8.8 Bodansky units; blood urea nitrogen 13 mg %, total plasma protein 6.5 gm %, normal serum electrolytes; protein-bound iodine 9.2 ,ug %, total iodine 12.0 ,ug %, thyroxine iodine 2.3 tig % (normal 2.5-7.0//Ag %); urinary vanilmandelic acid 80 mg/24 hr (normal 1.5-8.0), catecholamines unrecordably high, 5-hydroxyindoleacetic acid 3....

No abstract