Renal mass is usually a mass growing on the surface of the kidney or a cyst surrounded by the renal cortex, which can usually be detected during abdominal ultrasound. For benign kidney tumors, if the mass is less than five centimeters, the patient usually does not have any symptoms and usually does not need to deal with it, and it needs to be reviewed every six months. When the tumor is larger than five centimeters, there will be pain and discomfort in the lower back and abdomen. When the tumor is larger than seven centimeters, a kidney puncture biopsy is needed. Usually, if a kidney mass larger than seven centimeters in diameter is found, or if the mass grows rapidly within a short period of time, or if symptoms of painless hematuria are present, further enhanced CT of the upper abdomen is usually recommended, and a kidney aspiration biopsy is also needed to determine the nature of the mass.