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Medullary thyroid carcinoma (MTC) is a rare malignancy and compromises only 3 % of all thyroid carcinomas. MTC cells secret calcitonin, which serves as a sensitive tumor marker for screening and follow-up of MTC. Calcitonin screening in patients with nodular goiter allows for early diagnosis of MTC and surgical curative treatment. In 25 % of patients MTC occurs as an integral part of multiple endocrine neoplasia type 2 (MEN2), an autosomal dominant inherited tumor syndrome. It is caused by germline mutations in the RET protooncogene. In gene carriers early diagnosis and treatment through prophylactic thyroidectomy is possible. MTC is a slowly growing tumor with a good prognosis and 5 and 10 year survival rates up to 80 and 60 %. In the follow-up a dynamic risk stratification allows for a personalized disease management. In symptomatic and progressive metastasizing MTC tyrosine kinase inhibitors are an effective therapy.

Of 218 women with hirsutism 16 (7%) were found to have partial 21-hydroxylase deficiency, while 38 (17%) had partial 3 beta-hydroxysteroid dehydrogenase deficiency. Six women (3%) had a steroid constellation which resembled that of an augmented adrenarche. In the women with enzyme deficiency over-weight and abnormal menstruations were more frequent (50%) than in those without such deficiency (33%). The degree of hirsutism and age at diagnosis were similar in those with and those without partial enzyme deficiency. Furthermore, the diagnosis of partial enzyme deficiency could only be made with certainty by the ACTH stimulation test, because with sole measurement of basal levels (17-hydroxyprogesterone and 21-desoxycortisol in 21-hydroxylase deficiency, and 17-hydroxypregnenolone and dehydroepiandrosterone in 3 beta-hydroxysteroid dehydrogenase deficiency) the enzyme defects are in most instances not revealed.

OBJECTIVE To determine the importance of the molecular-genetic demonstration of germ-line mutation in the ret protooncogene for therapeutic measures in sporadic and hereditary medullary thyroid carcinoma (MTC). PATIENTS AND METHODS Several molecular-genetic tests were performed on DNA of 35 families with hereditary and 81 patients with the sporadic form of MTC (isolation of genomic DNA; PCR amplification; DNA sequencing: demonstration of mutation in codon 918 with restriction enzyme FOK 1). RESULTS A disease risk was demonstrated in 178 individuals among the 35 families, 159 of whom were investigated by molecular-genetic tests: 84 family members were found to be gene carriers. Germ-line mutation had already been suspected on clinical grounds in 76% of the carriers, 24% being discovered in a presymptomatic stage. Six children among the latter were treated prophylactically by thyroidectomy, histological evidence of C-cell hyperplasia being found in all of them, microcarcinomas in three of the older children. There were four patients among the non-carriers on whom thyroidectomy had been performed previously because of a false-positive pentagastrin-test; but germ-line mutation was now excluded. In one family, with familial MTC in two brothers, no mutation in ret-proto-oncogene has been demonstrated. The members of this family must now, as used to be routine, undergo a pentagastrin-test. Three of the 81 patients with "sporadic" MTC had a germ-line mutation, presumably a new one. CONCLUSION Molecular-genetic tests have further improved the management of families with hereditary MTC and they thus take first place among essential diagnostic procedures. The diagnosis of sporadic MTC can be confirmed by excluding germ-line mutation in the ret-proto-oncogene.