Medullary thyroid carcinoma (MTC) is rare in children. MTC is almost always inherited and occurs as part of a multiple endocrine neoplasia type 2A and B, due to germline mutation in the RET proto-oncogene. MTC in the pediatric population is most often diagnosed in the course of a familial genetic investigation. But when the child is the proband, a de novo mutation is most often founded. The main aim is to treat MTC before extrathyroidal extension occurs because when distant metastases are present, it is rarely curable. Treatment is based on total thyroidectomy with cervical lymph node dissection.
Keywords: hereditary disease; medullary thyroid carcinoma; multiple endocrine neoplasia.