Protein expression and mutational analysis of epidermal growth factor receptor in renal angiomyolipomas.

Renal angiomyolipoma (AML) is a benign but progressive tumor that occasionally requires non-surgical therapy and there appears to be a possibility that epidermal growth factor (EGF) is associated with pathogenesis of renal AML. The response to gefitinib, anti-epidermal growth factor receptor (EGFR) agent and a prime example of target therapy, reportedly has been correlated with the presence of mutations within the tyrosine kinase (TK) domain of EGFR or the expression of its truncated form, EGFR variant III. Therefore the purpose of the present paper was to investigate EGFR protein expression and gene mutations in exons 18, 19 and 21 in 40 renal AML. No EGFR gene mutations of TK domain were detected in any of the 40 cases studied and strong immunostaining was found in 5% of the renal AML cases. The present findings indicate that in renal AML, anti-EGFR treatment may not be promising but that there is a possibility that EGFR is associated with renal AML pathogenesis.