Treatment of sporadic nonmedullary thyroid carcinomas in pediatric age.

Nonmedullary thyroid carcinomas are rare malignancies in pediatric ages. The vast majority of them are papillary carcinomas with an overall survival of approximately 100%. Their outcome is independent of strong prognostic factors of adults, such as papillary carcinoma histological subtype, invasion into soft tissue of the neck, presence and site of distant metastases, relapse and type of surgery. In these ages, follicular carcinomas and poorly differentiated carcinomas are exceptional. Undifferentiated (anaplastic) carcinomas are practically absent. In most institutions, the therapy of choice for all pediatric thyroid carcinomas is the radical approach, aimed at the eradication at diagnosis of all clinical and subclinical neoplastic foci, both at thyroid, lymph node and distant level. It consists of total thyroidectomy and lymphadenectomy in children with clinically evident lymph-node metastases, followed by radioactive iodine therapy independent of histotype and stage. Recently, owing also to the high sensitivity to hormonal manipulation shown by pediatric papillary carcinomas, a conservative approach has been proposed for selected cases, consisting of the removal of only the grossly detectable disease followed by thyroid-stimulating hormone-suppressive hormonal therapy to control subclinical disease. Today, the existence of two therapeutic approaches, radical versus conservative therapy, should be considered whenever treating a child or adolescent with a nonmedullary thyroid carcinoma. Not least, permanent post-treatment complications of radical surgery and radioactive iodine therapy should be taken into account. The future tasks include the stratification of thyroid carcinomas into low- and high-risk cases, also including their molecular alterations and the possibility of a molecularly targeted therapy against tyrosine kinases involved in the pathogenesis of thyroid carcinomas.