Normal nephrogenesis occurs in the early stage of bilateral multicystic dysplastic kidneys.

We present a case report about bilateral multicystic dysplastic kidneys (MCDKs). Pregnancy was terminated at 21 weeks' gestation and the fetus was examined by autopsy. The kidneys were replaced by many cysts and there was no parenchyma. However, on histological examination, there was normal nephrogenesis amid the cystic/dysplastic tissue. This suggests that normal nephrogenesis occurs before the secondary changes leading to MCDKs.