ROLE OF BASIC FIBROBLAST GROWTH-FACTOR IN THE PATHOGENESIS OF NODULARGOITER

Thyroid epithelial cells are known to produce several growth factors a nd cytokines which influence thyroid cell growth and function in an au tocrine and/or paracrine manner. It is already known that insulin-like growth factor I (IGF I) is overexpressed in toxic adenomas whereas ep idermal growth factor (EGF) is found predominantly in thyroid neoplasi a. We now investigated the expression of bFGF by immunohistochemistry in thyroid tissue of patients with toxic adenoma (n = 27), cold nodule s (n = 27) and for comparison in Graves' disease (n = 5). In addition bcl-2-oncoprotein expression in these tissues were also detected by im munohistochemistry. Most of bFGF immunostaining was found in the conne ctive tissue of all thyoid tissues with a predominance in adenomas and in Graves' diseases. The collagen surrounding the thyroid follicles c lose to their basal membrane were homogeneously and intensively staine d. All the cytoplasm of fibroblast in the connective tissue were stron gly postive. Within the cytoplasm of only 2-10% thyroid epithelial cel l bFGF immunostaining was found without any difference between toxic a denomas or cold nodules. In the tissue of patients with Graves' diseas e, less than 2% of thyrocytes were stained. All thyroid epithelial cel l showed clearly an immunostaining for bcl-2-oncoprotein in nodular go iter as well as Graves' disease.