[Medullary thyroid carcinoma. Results of a family screening program].

During a ten-year period (1975-85) 56 patients with medullary carcinoma of the thyroid were under treatment. A family screening programme discovered such a tumour in the offspring of a 47-year-old female patient and her 56-year-old sister. In four of seven offspring from three lines of this family ultrasonography revealed changes in the thyroid. Positive preoperative pentagastrin test with stimulation of calcitonin as tumour marker resulted in the histological diagnosis of thyroid carcinoma.