Partial nephrectomy in a metachronous multilocular cyst of the kidney (cystic nephroma).

Cystic nephroma, that is multilocular cyst, is an uncommon renal neoplasm once thought to occur only unilaterally. We report a rare case of bilateral metachronous cystic nephroma in a child, which was treated by partial nephrectomy. Because of its benign nature this lesion is best managed by nephron sparing surgery. Exploration of the contralateral kidney is not necessary if modern radiological techniques are used. Magnetic resonance imaging angiography is an excellent noninvasive method to assess renal vessels before partial nephrectomy. Periodic ultrasound or computerized tomography screening of the remaining renal unit is recommended.