Medullary thyroid carcinoma (MTC) occurs as a sporadic form (75%) or as an autosomal dominant inherited familial disorder (25%) called familial MTC (FMTC) or as multiple endocrine neoplasia type 2 (MEN2) syndromes. Germ-line mutations in the rearranged during transfection (RET) proto-oncogene in exons 10, 11, 13, 14, 15 and 16 are known to be a cause of most of the familial forms. In this paper we report molecular genetic testing of 106 families with MTC (358 tested persons) from the Czech Republic in which we directly sequenced these six exons of the RET proto-oncogene. We detected germ-line mutations in 100% of MEN2B families (4/4 families), 90% of MEN2A families (9/10), 40% of FMTC families (4/10) and 7% of apparently sporadic MTC (6/82). Eleven different germ-line mutations were revealed. MEN2B was associated with mutation Met918 Thr in exon 16. In one MEN2B family beside this mutation the Tyr791 Phe was also found, which has not yet been reported. MEN2A was restricted to different mutations in exon 11 (codon 634). In FMTC and 'sporadic' MTC families the mutations in exons 10, 11, 13 and 14 were detected. The genotype/ phenotype correlations are given. Genetic testing revealed germ-line mutations in 23 index patients, 24 family members and excluded them in 53 relatives.

Differentiated thyroid cancers were found in mother and son. The diagnosis was made first in the boy where papillary and follicular cancer with lymph node involvement and lung metastatic dissemination was diagnosed at the age of 9. Treatment by surgery, radioiodine and thyroid hormones was highly effective. 1 year later, thyroid surgery was performed on his mother but the diagnosis of poorly differentiated follicular thyroid cancer was made only 4 years later when the primary tumour was already unresectable and distant metastases present. In spite of treatment, the disease followed a lethal course in the mother. The familial occurrence of’differentiated thyroid cancer is extremely rare and this report is the first where neither previous radiation exposure nor familial colonic polyposis were detected.

No abstract

Concentrations of selenium and rubidium in groups of subjects with hyperthyroidism, carcinomas, or adenomas and in controls were determined by neutron activation analysis with coirradiated inorganic standards and IAEA reference material. Se was decreased in all pathological groups with the greatest modification in thyroids with carcinomas. Rb was elevated in all pathological groups with the greatest increase in carcinomas as well. According to the literature, Se has a protective effect on carcinogenity as well as on biochemical pathways in thyroid cells. There are no data in the literature on the effects of Rb in those cells. On the grounds of the present results, it seems possible to use the trapping of Rb for diagnostic purposes in cases of pathologically altered thyroids.