Early Ultrasound Diagnosis of Renal Cancer

Early ultrasound diagnosis of renal cancer: B-mode ultrasound is the simplest and non-invasive examination method with high sensitivity in detecting renal cancer. In routine physical examinations, early tumors with no clinical symptoms and no changes in urography are often found. The ultrasound manifestation of renal cancer is a heterogeneous solid mass with low to medium echoes. Small renal cancer (diameter <2cm) sometimes shows high echoes and needs to be judged in combination with other examination methods.

1. The kidneys lose their normal appearance

When the tumor is small, the kidney contour does not change significantly. As the tumor grows, the kidney also grows. The tumor may protrude toward the surface of the kidney. In the early stages, it is clearly demarcated from the surrounding tissues. In the late stages, when renal cancer has extensive infiltration, there is no obvious boundary.

2. Abnormal renal parenchymal echo

Abnormal echo masses appear in the renal parenchyma, with clear boundaries and a sense of sphere. The internal echoes are variable. Medium-sized tumors are mostly low-echoic, and a few are strong or mixed echoes. When there is bleeding, necrosis or liquefaction inside the tumor, there will be irregular edge-free echo areas locally. When there is calcification in the tumor, there will be dot-shaped or block-shaped strong echoes with acoustic shadows.

3. Renal sinus compression and deformation

When the tumor grows inward and compresses or invades the renal sinus, the renal sinus may become concave, displaced, interrupted, or even unclear. In a few cases, the renal pelvis and calyx may dilate and accumulate water.

4. Abnormal changes in blood vessels around the kidney

In the late stage of renal cancer, when cancer cells invade the renal vein or inferior vena cava, the ipsilateral renal vein or inferior vena cava will widen and become blocked, with mixed echoes in the form of dots or masses.