Genetic and Clinical Features of Medullary Thyroid Carcinoma: The Experience of a Single Center in Costa Rica.

. Activating mutations in the gene leads to medullary thyroid carcinoma (MTC). Guidelines encourage performing analysis in subjects with hereditary and sporadic disease. . . Observational, case series report study. . Subjects diagnosed with MTC, with a thyroidectomy performed in a single center in Costa Rica between the years 2006 and 2015. . Pre- and postoperative calcitonin, mutation, and neck ultrasound and tomography were obtained. . 21 subjects with histological diagnosis of MTC were followed up. The average age at diagnosis was 52.0 ± 15.7 years. The preoperative mean value of calcitonin was 1340 ± 665 pg/mL. Evidence of mutation was found in 26.3% of the patients, with only 2 of them grouped in the same kindred. We found statistically significant differences in mean ages between mutated (38.4 ± 20.2 y) versus nonmutated (54.6 ± 11.8 y, = 0.04). There were no significant differences regarding tumor size, metastases, and surgical reintervention. . We report the results of mutation analysis in subjects with MTC in a single center of Costa Rica. The availability of this tool increases the probability of identifying familial MTC, with the benefit of detecting affected subjects and their relatives at an earlier age.