ABSTRACT:The incidence of follicular thyroid cancer (FTC) varies in different countries and is more common in women increasing with age in general population. There is lack of similar data concerning paediatric population. FTA is difficult to diagnose by fine-needle aspiration, thus any follicular thyroid tumor need to be excised for further identification of its malignant or benign character. Overwhelming majority of FTC cases are asymptomatic and euthyroid, which exacerbate the early diagnosis and clinical manifestation of thyroid nodules. Therefore they are detected by routine physical examination without clinical signs of thyroid dysfunction. USG examination is useful for monitoring nodule size and for the fine-needle aspiration (FNA) of nodules and cysts, but not for identifying of cancers. We present a case report of a 3.5 years old child with swelling of the left lateral-anterior aspect of the neck without clinical complaints that was first noticed about 4 months before. There was no family history of any cancers, nor a history of exposure to radiation. TSH and free T4 levels, as well as autoantibodies against thyroid gland were measured and found to be in normal ranges. A nodule of 4.2cm in diameter by USG examination, and follicular neoplasm by ultrasound-guided FNA has been revealed. Surgical excision -lobectomy was performed with further histology of the tumor. The final pathohistological diagnosis was follicular carcinoma, which is very rare state in children. Postoperatively the boy was not administrated levothyroxine suppressive therapy to escape unnecessary side effects from excess of hormone intake. He is under intensive monitoring up to now. After 5 years of monitoring no other nodule development was dated, euthyroidism clearly remain, lymphadenopathy of neck is absent.