Renal cell carcinoma mimicking an angiomyolipoma on ultrasound

Renal cell carcinoma mimicking an AML on ultrasound. Ultrasound of the left kidney (arrows, A) reveals a small echogenic mass. CT without contrast (circle, B) fails to detect fat in the lesion. Following contrast (arrowhead, C), the lesion heterogeneously enhances; the lesion was resected and proven to be a small renal cell carcinoma.