Ultrasound classification of solitary renal cysts in children

The modified Bosniak classification system demonstrated good inter-observer agreement, and identified the single tumor as a complex cyst. The vast majority of solitary renal cysts in children are simple and if asymptomatic, they require no other imaging evaluation. Complex renal cysts are uncommon and should be evaluated with a pre-intravenous and postintravenous contrast CT scan to exclude a tumor.121Figure. Longitudinal color doppler US of a complex (grade III by both radiologists) left renal cyst in a 7.2 year-old boy. The child presented with gross hematuria. Ultrasound shows a septated cystic mass with vascularity of the septations (arrowheads) and cyst wall (arrow). Radical nephrectomy was performed with pathologic diagnosis of multiloculated cystic nephroma.