When should thyroidectomy be performed in familial medullary thyroid carcinoma gene carriers with non-cysteine RET mutations?
GROUND: Once familial medullary thyroid carcinoma gene carrier status is established, thyroidectomy must be performed in infancy for mutations in exon 10, but in familial medullary thyroid carcinoma with non-cysteine RET mutations, which is characterized by a late onset of C-cell disease, the appropriate timing of thyroidectomy is unclear. METHODS: We analyzed the cases of 76 patients who underwent thyroidectomy (mean age, 35.2 years); 66 patients underwent concomitant lymphadenectomy. RESULTS: Before the operation, 35 patients had abnormal basal calcitonin levels. Nine and 30 patients had negative or positive pentagastrin test results, respectively. We found normal thyroid in 4% of the patients, C-cell hyperplasia in 29% of the patients, medullary thyroid carcinoma in 67% of the patients (microscopic in 82.4%), and nodal metastases in 19.6% of the patients. The aggressiveness of the disease varied significantly between those patients with preoperative positive pentagastrin test result