Case of the Day: Name that Renal Mass, the importance of CEUS

Teaching Point:

One of the biggest challenges in renal imaging is differentiating solid from cystic lesions. Cysts are extremely common and become more so as a patient ages. Cysts can be complicated by hemorrhage which can make the mass appear solid, mimicking a potential cancer. Determining whether a mass is cystic or solid is crucial in diagnosing potential malignancies of the kidneys.

Teaching Point:

Any blood flow to a renal mass indicates a solid lesion. Renal Mass enhancement patterns are compared to the background renal cortex and in this example the mass enhances less than the kidney parenchyma. This mass is considered Hypoenhancing.

Teaching Point:

Papillary renal cell carcinomas account for up to 1/5 of renal malignancies. They are generally hypoechoic on greyscale ultrasound and are also characteristically less vascular than the more common clear cell subtype. They show overall hypoenhancement compared to the normal renal cortex in the arterial phase.

Renal masses unlike the liver do not have a portal phase. However, they have a venous phase in which washout can be identified, which is reduced enhancement in the lesion compared to the background renal parenchyma.

The addition of CEUS confirms a sold vs cystic mass but can help diagnose the type of Renal Cell pathology.