Ureteric Bud-derivatives in Wilms Tumor and Nephrogenic Rest.

BACKGROUND/AIM:Recent studies suggest that not only the nephrogenic blastema but also the ureteric bud is involved in oncogenesis of Wilms' tumor (WT). However, the occurrence of ureteric bud (UB) derivatives in nephrogenic rest is not yet known. The aim of our study was to find UB derivatives in WT. MATERIALS AND METHODS:Keratin 17 (KRT17) is expressed exclusively in UB in foetal kidneys. In this study KRT17 immunohistochemistry was used to detect UB-derivatives in 21 triphasic, 2 stromal and 3 epithelial predominant WTs and 9 nephrogenic rests. RESULTS:We have detected KRT17 positive tubular structures resembling UB in 3 of 9 nephrogenic rests and 15 of 26 WTs. CONCLUSION:Not only the metanephric blastema but also the UB is involved in the histogenesis of nephrogenic rest and WT.