[Thyroid carcinoma in children and adolescents].

Approximately 10% of thyroid cancers are present in patients less than 21 years of age, representing 3% of all cancers of children and adolescents, with predominance in females 2:1 in relation to males. Thyroid cancers in this age group are usually papillary (90%), bilateral, multifocal and bigger in size compared to adults. Capsule invasion and lymphatic and pulmonary metastases are more frequent in children. Radiation sensitivity seems to represent an important factor in prepubertal patients. Familial history is reported in 5% of the cases. Genes such as RET/PTC, RAS and BRAF are usually involved in thyroid carcinogenesis in this age group. Cervical adenomegaly is a common clinical presentation, but does not represent a poor prognostic factor in children. Ultrasound and fine needle aspiration biopsy are valuable diagnostic procedures. Surgery is the preferred treatment including thyroidectomy and ganglionary excision, followed by ablative radioiodine therapy. L-thyroxine replacement with suppressive dosage should be employed targeting chronic TSH suppression. Long-term prognosis is usually better in children when compared with adults. Plasma thyroglobulin measurement is also useful to detect residual thyroid cancer disease.