The paper reviews briefly the role of various radiopharmaceuticals for scintigraphic diagnosis and follow-up of thyroid malignancies. The emphasis is given to thyroglobuline quantification and 131-I whole-body scintigraphy as specific and accurate methods in the follow up of differentiated thyroid cancer. Recombinant human TSH is introduced as a promising, safe and effective method to stimulate 131-I uptake and Tg secretion without the disadvantages of induced hypothyroidism.

Fine-needle aspiration is a low-cost diagnostic tool with principal value in determining which patients with thyroid nodules should undergo surgery. Team work and close cooperation among endocrinologists, surgeons, and pathologists are essential for success. Cytologic criteria for diagnosis of the most frequent malignancies found in thyroid aspirates have been provided. The unsolved problem of the so-called »follicular or oxyphilic lesion or neoplasia« will be investigated by immunocytochemistry.

Numerous pathohistologic criteria, difficultes and pitfalls in the process of diagnosing of thyroid carcinoma are discussed. Benign hyperplastic papillae may be present in colloidal cystic goiter and hyperplastic goiter. These structures are lined by cells with normochromatic nuclei and do not disturb the thyroid tissue architecture. Papillae in papillary thyroid carcinoma have cells with ground –glass, hypochromatic nuclei.