Expanding role of fine-needle aspiration cytology in thyroid diagnosis andmanagement

In non-iodine-deficient areas, 4% to 7% of the population are reported to h ave thyroid abnormalities. Prophylactic operations of these nodules in the thyroid are not indicated and not cost-effective, as at least four of five nodules are colloid goiter and only a few are malignant. The need for a rel iable preoperative diagnosis is great and fine-needle aspiration (FNA) is n ow considered the first choice during workup for thyroid nodules. The steps in the FNA procedure are clinical examination and localization of the targ et lesion, aspiration, preparation of smears, and collecting material fur a ncillary microscopy techniques. All these steps must be exercised to allow optimal use of FNA. It can also be combined with various other methods, suc h as immunohistochemistry of thyroglobulin and calcitonin, analysis of nucl ear DNA, DNA preparation for molecular biology analyses, and magnetic reson ance spectra. The accuracy of the clinical routine in our unit was evaluate d by studying the 5-year outcomes of almost 4000 FNAs of the thyroid. The r esults were good, with only a few false-negative and false-positive results ; but the problem of differentiating follicular adenoma from follicular car cinoma remains a significant problem. It is now well established that FNA b iopsy and cytology is the best modality available for the workup of thyroid nodules and is widely utilized in endocrine surgical centers worldwide.