[LOCALIZED CYSTIC DISEASE OF THE KIDNEY IN A 6-YEAR-OLD GIRL].

Localized cystic disease of the kidney (LCDK) is a rare, non-hereditary, non-progressive benign cystic renal condition. It is found primarily in adults, and is rarely reported in children. To date, only 5 prepubertal cases of LCDK have been reported in the literature. In this report, we present a case of LCDK that was difficult to differentiate from malignant renal tumor in a 6-year-old girl. Nephron-sparing surgery could not be performed.A 6-year-old girl with no past medical history presented with gross hematuria and right-sided abdominal pain. An abdominal ultrasound at a local hospital showed multiple variable-sized cysts throughout the right kidney. She was referred to our hospital for further evaluation. Computed tomography demonstrated that the region between cysts was slightly enhanced in some part of the lower pole and was diagnosed III in the Bosniak classification. Nephrectomy was performed for possible cystic renal neoplasm. After surgery, a diagnosis of LCDK was made by histopathological examination.