Preventive thyroidectomy in patients with hereditary medullary thyroid carcinoma found heterozygote for mutant RET proto-oncogene.

The currently available genetic tests for identification of the RET proto-oncogene mutation offer the possibility of prospective successful therapy before the hyperplasia of C-cells evolve to Medullary Thyroid Carcinoma. We present our experience regarding the preventive thyroidectomy of family members with history of Medullary Thyroid Carcinoma, who were found to be heterozygote for mutant RET proto-oncogene. We have retrospectively reviewed 19 members of 6 families with history of Medullary Thyroid Carcinoma, who were heterozygote for mutant RET protooncogene and underwent prophylactic thyroidectomy. All patients included in this series were below twenty years of age. The Medullary Thyroid Carcinoma was asymptomatic and the mutation of RET protooncogene has been also documented pre-operatively in all of them. All patients had undergone total thyroidectomy, while 1 with pheochromocytoma had undergone also left epinephridectomy. Fourteen patients (73.68%) had undergone lymph-nodes resection (in 10 of them the resection was central, in 3 unilateral and in 1 bilateral). Although none of our patients suffered from hyperparathyroidism, 7 parathyroid glands have been also resected from 3 patients, while auto-transfusion has been performed in one. In all patients, preoperative measurement of the calcitonin blood levels before and after stimulation with pentagastrin has been performed.