RESUMO
Aggressiveness and age of manifestation of medullary thyroid cancer depend on the risk level of germline RET mutations. For high-risk mutations, preventive thyroidectomy is recommended at young age. In recent years, endoscopic operations for thyroid cancer were introduced in clinical practice. But such experience in pediatrics is very limited. We present a case report of a male patient, 6-year-old with the high-risk germline mutation С634R in RET gene. Close relatives (mother, cousin, and native sister) of the proband, were treated for medullary thyroid cancer. Also, his grandmother on the maternal line and her native brother died at the age of 38 and 37 years because of medullary thyroid cancer progression. Since 3 years old, our patient was under regular exams. At the age of six, calcitonin level was 8 ng/mL, and no evidence of pathology on ultrasound. According to recommendations of American Thyroid Association from 2015 (ATA 2015), preventive thyroidectomy was planned. This operation was performed by transoral vestibular approach. Oral nutrition started on the first day after the operation and the patient was discharged from the hospital. No major complications were observed. Transitory paresthesia and slight edema of the submental compartment were noticed. Consider this, endoscopic operation on the thyroid gland can be performed, as a preventive procedure, for RET gene germline mutation carriers in young age. This method helps avoid scars on the skin of the anterior neck.