Medullary thyroid carcinoma. The need for early diagnosis and total thyroidectomy.

Forty patients with medullary thyroid carcinoma and 3 patients with C-cell hyperplasia were studied. Seventeen (40%) cases were sporadic and 26 (60%) were hereditary. Eight patients had type lla multiple endocrine neoplasia, 7 patients had type llb multiple endocrine neoplasia, and 11 patients had familial nonmultiple endocrine neoplasia medullary thyroid carcinoma. Mean follow-up was 6.3 years, with actuarial survival of 88% and 78% at 5 and 10 years (22 and 13 patients), respectively. Seven patients died 1.5 to 10 years after the initial operation; all had advanced disease at presentation (6 with distant, 1 with lymph node metastasis). No deaths occurred in patients with familial nonmultiple endocrine neoplasia medullary thyroid carcinoma, C-cell hyperplasia, or medullary thyroid carcinoma limited to the thyroid gland. Nineteen (68%) of 28 patients diagnosed without screening had regional or distant metastases, whereas only 6 (40%) of 15 patients diagnosed by screening had metastases. Twenty-six patients treated initially with total thyroidectomy and central neck clearance required an average of one reoperation, whereas those with lesser initial procedures required an average of two reoperations. We concluded that (1) familial nonmultiple endocrine neoplasia medullary thyroid carcinoma, early medullary thyroid carcinoma or C-cell hyperplasia, and asymptomatic patients have a good prognosis; (2) screening for medullary thyroid carcinoma by measuring serum calcitonin levels results in earlier diagnosis; and (3) total thyroidectomy and central neck clearance is the procedure of choice for medullary thyroid carcinoma.