Kidney cancer is the most common type of kidney malignancy. Pathologically, it is mainly divided into clear cell renal cell carcinoma, chromophobe renal cell carcinoma, papillary renal carcinoma, and collecting duct carcinoma, with clear cell renal cell carcinoma being the most common. Ultrasonographically, it usually appears as round or oval masses, varying in size but generally around 2-4 cm, exhibiting low to medium echo patterns. If the tumor is larger, greater than 5 cm, it may show changes in mixed echo patterns due to possible internal bleeding or cystic changes when the tumor is large. When kidney cancer is suspected on ultrasound, it is best to further proceed with enhanced MRI or enhanced CT scanning.