RESUMEN
Well-differentiated thyroid carcinoma in children and adolescents is rare but demonstrates aggressive behavior. Gross lymph node metastases and distant metastases are common upon first clinical presentation. During a 33-year period (1981-2014) at the Institute of Oncology and Radiology of Serbia, 62 children and adolescents underwent surgery due to well-differentiated thyroid carcinoma. Mean age was 16.7 (range 7-21) years. At the time of diagnosis 6% of patients had lung metastases. Total thyroidectomy or completion thyroidectomy was performed for all patients followed by central neck dissection and frozen section examination of jugular-carotid compartments. Median follow-up was 10.9 (range 0.69-33.05) years and median tumor size was 20 (range 2-60) mm. Papillary carcinoma was found in 96%, and follicular and Hürthle cell carcinoma in 2% of patients. Multifocal tumors were found in 50% and capsular invasion in 60% of patients. Lymphonodal metastases in either central or lateral neck compartments were found in 73% of patients. Multifocality and capsular invasion were significantly more frequent in patients less than 16 years of age (both p < 0.01). Median disease-free interval had not been reached and overall survival rate was 100%. Well-differentiated thyroid carcinoma in children and adolescents is characterized by a high rate of loco-regional aggressiveness, multifocality, capsular invasion, lymph node metastases and distant metastases at the time of diagnosis. Adequate surgical approaches should be performed for both primary and recurrent disease in young patients with well-differentiated thyroid carcinoma in order to achieve loco-regional disease control and longer disease-free survival.