The prevalence of thyroid nodules in children is lower than in adults. The prevalence of thyroid nodules in children (diagnosed by palpation) in the United States is about 2%, with an annual incidence of about 7 per 1000 [35]. In China, the prevalence of thyroid nodules (diagnosed by ultrasound) in children was reported to be 7.04%, and multiple nodules accounted for 66.7%, with a male to female ratio of 1:1.4. Most malignant thyroid nodules in children are DTC, and about 5% are MTC. The incidence of thyroid cancer is higher in females than in males in children over 10 years of age [37]. The evaluation of thyroid nodules in children, including history taking, physical examination, laboratory index tests, imaging and FNAB, is essentially the same as in adult patients. the sensitivity of FNAB in diagnosing thyroid cancer in children is 86-100% and the specificity is 65-90%. Treatment of thyroid nodules in children is also essentially the same as in adult patients. Surgery is the primary treatment for malignant/suspect malignant thyroid nodules in children. The management of thyroid nodules in children differs from that of adult patients in the following aspects: ① CT of the neck should be performed with caution, as high dose radiation exposure may increase the chance of malignancy in children with thyroid nodules. ②
The percentage of malignant thyroid nodules in children is higher than in adults, up to about 20%, and “hot nodules” confirmed by thyroid nuclide imaging are also at risk for malignancy. Therefore, children with “hot nodules” should be further evaluated. ③
Malignant nodules in children are usually multifocal and have a higher risk of lymph node metastases and even distant metastases. Therefore, total or near-total thyroidectomy and postoperative 131I therapy are recommended for the treatment of a large proportion of children with DTC. ④
Children with thyroid nodules who have a family history of MTC or MEN2 type are recommended to be tested for mutations in the RET gene [41]. The incidence of MTC is significantly higher in mutation-positive individuals. Such patients should undergo prophylactic total thyroidectomy, with the age of resection depending on the risk of developing MTC (as assessed by the RET gene mutation locus). ⑤
The long-term survival rate for DTC is more than 90%; for MTC, the 5- and 15-year survival rates are more than 85%, but the 30-year survival rate is lower (about 15%). The recurrence rate of thyroid cancer in children is about 10-35%.