Thyroid carcinomas are the most common type of endocrine neoplasia. They represent approximately 1% of all new cancer diagnoses each year, and the rate of new cases is increasing. We report the case of a 54 year old man admitted to our department for a giant right anterolateral cervical tumor, measuring about 15 cm in diameter, diagnosed by fine-needle biopsy as follicular thyroid carcinoma. We performed a total thyroidectomy and the histological evaluation established the diagnosis of follicular variant of papillary thyroid carcinoma. The paper refers to the etiopathogenesis, clinical symptoms, diagnosis treatment and prognosis of well-differentiated thyroid carcinoma. [ABSTRACT FROM AUTHOR]