Abstract: Incidence rate of differentiated thyroid carcinoma in teenager is not high. It has some different characteristics compared to adult differentiated thyroid carcinoma. Such as larger tumor at diagnosis; greater prevalence of neck lymph node and distant metastases at diagnosis; more sodium-iodide symporter expression; high recurrence rate but higher overall survival rate. ¹³¹I administration to remove residual thyroid tissue and treat metastases is still one of the important approaches after surgery.