[Differentiated tumor of the thyroid in children and adolescents]

Differentiated thyroid carcinoma (DTC) is rare in young patients and represents 0,5 to 3,0% of childhood carcinomas. The incidence increases with age: a peak incidence is observed between 15 and 19 years of age. DTC in children is frequently associated with greater risk of cervical lymph node involvement (60-80% of cases) and lung metastases at diagnosis in 20% of patients. However the prognosis for these patients is better when compared with that of adults, despite a high incidence of relapse, leading to reoperation. Young age (<16 years), lymph node involvement or distant metastases at diagnosis and some histopathologic characteristics have been suggested as predictive factors of recurrences. The records of 33 patients with DTC in a 14-year period (1990-2004) were reviewed. There were 31 females and 2 males who ranged from 11 to 21 years. At the diagnosis 15 patients had disease confined to the thyroid, 18 had additional lymph node metastases in the neck; one of them had also lung metastases. Total thyroidectomy (TT) was the elective approach in all patients (4 cases videoassisted). TT was associated to functional neck dissection in 21 cases. 131I was administrated to 28 patients (3,7 GBq as ablative dose): 11 of this received further radioiodine treatments (mean 7,4 GBq) because of elevated serum thyroglobulin levels and presence of loco-regional or lung metastasis at diagnostic total body scan after 131I treatment. The overall survival rate was 100% at a follow up of 4 months to 14 years.