Clinical Management of Thyroid Nodules in the Areas of Various Iodine Supply

Abstract

The thyroid nodules constitute an important diagnostic problem mainly because various benign lesions must be distinguished from malignant neoplasms. This problem is of particular importance in endemic and postendemic areas where there are a lot of patients with multiple thyroid nodules. In such areas the majority of thyroid lesions is nonneoplastic and develop usually when diffuse goitre transforms into nodular one (Laurberg et al;. 2010, Slowinska-Klencka et al., 2002, 2008). Other non-neoplastic thyroid lesions may develop due to thyroiditis (acute thyroiditis, de Quervain disease, and autoimmune chronic thyroiditis). The frequency of revealing thyroid cancer – in comparison to malignancies in other organs – is relatively low. On the other hand, it is the most common cancer of endocrine glands, and the incidence of thyroid cancer is continuously increasing (Hughes et al., 2011; Sipos & Mazzaferri, 2010). This increase is partly related to the improvements to efficacy of preoperative diagnostics, but whatever is the nature of the observed higher incidence of the thyroid cancer it focuses the interests of physicians. It should be stressed that epidemiological assessments based on clinical data do not reflect the true incidence of the thyroid cancer, as it is found in as much as 30% of cadavers if the thyroid is serially examined during autopsy (Fukanaga & Yatani, 1975; Harach et al., 1985). In majority of such cases these cancers are subclinical papillary microcancers (with diameters below 10 mm) that are usually not diagnosed in alive patients. However, recently it has been shown that cytological examination of small thyroid lesions reveals invasive cancers (with the presence of cancer cells in lymph nodes and infiltration of the thyroid capsule) with a surprisingly high frequency (Chow et al. 2003; Kang et al., 2004; E.K. Kim et al., 2002; Lin et al., 2005; Nam-Goong et al., 2004; Papini et al., 2002, Slowinska-Klencka et al., 2008).