IGF-II, bFGF and their receptors In affected tissues of macrodactyly and the pathogenesis of macrodactyly

Objective To examine the expression of insulin-like growth factor Ⅱ (IGF-Ⅱ ), basic fibroblast growth factor (bFGF) and their receptors ( IGF-1R and FGFR2 ) in affected tissue of macrodactyly,and to analyze the pathogenesis of macrodactyly and the involvement of nerves. Methods Tissues that were resected from 15 cases of macrodactyly underwent histological and immunohistochemical analysis to semi-quantitatively analyze the expression of IGF-Ⅱ , bFGF, IGF-1R and FGFR2. Tissues obtained from resection of polydactyly underwent the same processing and served as control. Results Nerve involvement was seen in all the 15 eases. The nerves were thickened and histological examination showed pathology pertinent to fibrolipomatous hamartoma of nerve. When compared with control tissues, the expression of IGF-Ⅱ , bFGF, IGF-1R and FGFR2 was significantly increased in macroactyly tissues. Schwann ceils and axons in the macrodactyly tissue demonstrated significantly higher expression of IGF-Ⅱ, bFGF and IGF-1R than the fat and fibrous tissue, whereas expression of FGFR2 was not statistically different. Conclusion There is increased expression of IGF-Ⅱ , bFGF and their receptors in affected tissue of macrodactyly. In addition, there is distinctly higher expression of these two growth factors in peripheral nerves than in other tissues. Key words: Hand deformities,congenital;  Immunohistochemistry;  Insulin-like growth factor