[Solid or cystic renal mass]

In a patient with a bacterial nephritis and renal stones an incidental finding of a complicated renal cyst on the opposite side was made on CT scan. In contrast to the CT findings, on ultrasound examination the lesion appeared to be a solid mass. The injection of ultrasound contrast material confirmed this by showing an enhancement of the whole lesion. Finally, the histological finding after nephrectomy results in a renal cell carcinoma pT1a. In this situation contrast enhanced ultrasound seems to be more sensitive than CT scan in detecting the perfusion of a renal mass.