We report a study of a family with C cell hyperplasia and hypercalcitoninemia in which no cases of medullary carcinoma have yet occurred and which lacked an identifiable causative RET mutation.
We registered 60 multiple endocrine neoplasia (MEN) 2A patients, 12 familial non-MEN medullary carcinoma (FMTC) patients, and three MEN2B patients with a confirmed RET germline mutation.
RET/PTC mutations are often discovered both in papillary and in medullary carcinomas, while B-RAF mutation is typical of papillary and anaplastic histologies.
The occurrence of mutations in the RET protooncogene has been investigated in 12 multiple endocrine neoplasia type 2A families and 18 cases of sporadic thyroid medullary carcinomas and pheochromocytomas.
Prophylactic surgery for patients carrying a positive RET proto-oncogene proved to be highly effective in curing those likely to experience the development of a medullary carcinoma.