Differentiated thyroid carcinoma of children and adolescents

Differentiated thyroid carcinoma is the most frequent malignant endocrine tumor of children and adults. Although uncommon during childhood, it is an important consideration in the differential diagnosis of any thyroid mass in a young patient. The risk for malignant disease, clinical features, genetic alterations, and clinical outcomes are different for children. The most common presenting symptoms of thyroid carcinoma in children are thyroid nodules and lateral neck masses. The latter are frequently not associated with a palpable abnormality of the thyroid gland. For patients younger than age 21 years, the risk for malignant disease in a solitary thyroid nodule is greater than for older patients and is generally reported to be between 30% and 50%. Mutations in ras oncogenes and the α-subunit of guanosine triphosphate binding proteins are more common in thyroid carcinoma from adults than children. In contrast, mutations leading to activated recombinant ret oncogenes (ret/papillary thyroid carcinoma) are more common in papillary thyroid carcinoma of children. The management of nodular disease, in particular malignant disease, of the thyroid remains controversial in young patients. With aggressive treatment, the outcome is generally favorable. Disease-specific mortality of less than 10% is frequently reported, along with recurrence rates of approximately 20%. However, aggressive treatment exposes all patients to the risks of extensive surgery and radioactive iodine. For young patients, younger than age 5 years, the surgical risks are great. Also, the risks of radioactive iodine ablation are largely unknown but may be greater for younger children than for older children or adolescents. For these reasons, diagnostic and treatment options should be individualized for all young patients with differentiated thyroid carcinoma.