DIAGNOSIS OF THYROID-CARCINOMA

Despite being one of the most frequent neoplasms occurring in the endo crine system, thyroid carcinoma is, nevertheless, a relatively rare ev ent (0.5-1.5% of all malignant tumours in man); the differentiated for ms are the most prevalent and are characterized by a high mean surviva l rate, whereas the very aggressive forms are rare and prognosis is un favourable, Diagnostic evaluation of carcinomatous lesions, particular ly in the early stages, may give rise to considerable difficulties at a clinical level due to the differentiation of the benign lesions, whi ch are a frequent finding. The traditional clinico-semeiological and i nstrumental parameters, which, in the past, were used in the assessmen t of suspected malignancy, should not be considered as markers of mali gnancy; however, exposure to ionizing radiations during childhood may have a well defined role of risk. Following the recent progress in gen etic and molecular studies, it is now possible to exploit genetic-mole cular tumor markers and, at present, thyroid medullary carcinoma may b e identified also in the absence of clinical evidence, particularly th e familial form, thus allowing suitable prophylaxis in those subjects with specific genetic impairment (e.g. preventive thyroidectomy in inf ancy). Since no discriminating clinico-semeiological parameters are av ailable, considering the aspecificity of scintigraphic findings and th e lack of reliability of echographic imaging in providing data which e nable us to distinguish a rare neoplastic pattern from the more freque nt finding of a benign thyroid mass, fine-needle aspiration (FNA) cyto logy may today be considered the technique of choice in the screening of the thyroid nodule, Our experience in over 12,000 nodular lesions s ince 1982, has confirmed that the cytological examination is the most discriminating investigation, diagnostic reliability being far greater than that of traditional techniques, Considering the high frequency o f thyroid nodule disease which rarely harbours a carcinomatous lesion, a very scrupulous diagnostic algorithm is mandatory. The FNA cytology , together with morphofunctional and immunological examinations, as we ll as dynamic exploration of the thyroid hypothalamo-pituitary axis, w hich allows a nosographic picture of the thyroid nodule disease, provi des a more discriminating appraisal for the surgical approach to a sin gle, solitary or prominent nodule.