Unusual case of multilocular cystic nephroma treated with nephron sparing technique: a case report.

Multilocular cystic nephroma is an unusual entity of uncertain etiology that can affect children and adults equally. This lesion is believed to be part of a spectrum of renal cystic disorders with multilocular cyst and cystic Wilms' tumor representing the two extremes and usually presents with a benign character. We report a 22-year-old female who presented with a painful right renal mass and gross hematuria. After a series of examinations including abdominal ultrasound, computed tomography, and angiography, she underwent partial nephrectomy under the impression of benign lesion. The pathologic examination showed that it was a multilocular cystic nephroma. At the 11-month follow-up, the patient was completely asymptomatic and free of recurrence and metastasis.