[Value of the assay of plasma carcinoembryonic antigen and thyrocalcitonin in the detection of medullary cancer of the thyroid with amyloid stroma. Results of a familial survey of 47 subjects].

During a study of 80 subjects from the same family, 47 persons underwent clinical examination and blood sampling for carcinoembryonic antigen and thyrocalcitonin. A preliminary investigation had shown that two members of the family had histologically confirmed amyloid stroma MTC, 2 others had probable malignant disease, 3 children died of intestinal obstruction in the neonatal period, and a fourth child operated for megacolon when 3 days old was the descendant of 2 subjects with probable thyroid carcinoma. Three years later, the study was updated and concentrated on the patients with the highest risk of developing malignant disease. The diagnosis was confirmed in one patient considered to have probable MTC. One case of malignant disease was discovered in a child considered to be normal 6 years previously. Three other patients, considered to be normal 6 years before had very probable MTC. These results indicated that familial investigations including plasma calcitonin measurements after pentagastrin stimulation, are valuable when amyloid stroma MTC is diagnosed in one member of the family. This test should be repeated periodically. The surgical indications in patients with abnormal responses should take into consideration the psychological context.