[Recent findings on the etiopathogenesis of multinodular goiter. II. Thyroid growth factors].

In the last ten years several experimental data have suggested that growth factors may play an important role in modulating thyroid growth and function. Epidermal Growth Factor (EGF) is present in large quantities in thyroid tissue, where it appears to stimulate DNA synthesis and inhibit cellular function. Insulin-like Growth Factors (IGFs), Interleukin I (IL-I) and Fibroblast Growth Factor (FGF) show the same stimulation on cell proliferation. On the contrary Transforming Growth Factor beta (TGF-beta) and somatostatin display inhibitory effects on follicular growth. Therefore it is likely that growth factors' altered production and/or their receptors abnormal expression on the thyroid cells surface might be involved in the development of multinodular goiter and some thyroid neoplasms.