Problems of cytological diagnosis of follicular thyroid cancer

Identity of cytological signs of follicular thyroid adenoma and well-differentiated follicular thyroid cancer make difficulties for differential diagnosis. Fine-needle biopsy is a screening-test for the detection of nodules with high risk of malignization. The final diagnosis can be made after morphological examination of surgical specimens because capsular and/or vascular invasion is a compulsory condition for follicular thyroid cancer.