Thyroid carcinoma is relatively rare in children.

Thyroid cancer , the most common pediatric endocrine neoplasm, represents 1–1.5 % of all pediatric malignancies and 5–5.7 % of head and neck malignant tumors.

Only 5 % of all thyroid cancers occur in children and adolescents.

Thyroid nodules occur in 4–7 % of the general adult population but in only 1–2 % of the pediatric population.

Whereas 5 % of thyroid nodules in adults are malignant, in the pediatric population, the percentage of malignant thyroid nodules is 26.4 %. Pediatric thyroid nodules are four times more likely to be malignant than adult thyroid nodules.

The incidence of thyroid carcinoma is 2–3 times more in girls than boys and commonly occurs between 7 and 12 years of age.

Prior radiation to the neck in childhood is established as a causative factor in development of thyroid cancer . Radiation and chemotherapy for other pediatric malignancies also have been implicated in the etiology of thyroid malignancy. Children who undergo pretreatment radiation therapy prior to bone marrow transplant and children who undergo primary radiation treatments for Hodgkin lymphoma are at increased risk for thyroid cancer.

Thyroglossal duct cysts carry an increased small risk of malignant transformation.

Most childhood thyroid nodules are asymptomatic and are detected by parents or by physicians during routine examination.

About 50 % of children with thyroid carcinoma present with nodular thyroid enlargement as the presenting symptom.

Follicular adenoma is the most common cause of solitary thyroid nodules in the pediatric population; however, solitary nodules in children reportedly have a 20–73 % incidence of malignancy.

A painless noninflammatory metastatic cervical mass is the presenting symptom in 40–60 % of patients.

Malignant lesions are usually papillary and follicular carcinomas.

Papillary thyroid cancer is by far the common thyroid malignancy in children.

Medullary thyroid cancer (MTC) :