Suprarenal cysts examined for benign and malignant can be clearly diagnosed by color Doppler ultrasound, ultrasound-guided puncture, and urine examination. 1. Color Doppler ultrasonography: each benign cyst can be found to have a thin wall without septum, calcification, and solid components; malignant cysts may have thickened irregular, smooth cystic walls, septum, and contain enhanced soft-tissue components adjacent to, or independent of, the cystic walls and septum. 2. Ultrasound-guided puncture: malignant is usually bloody, dark brown, and tumor cells can be found in the cystic fluid; whereas benign cystic walls are usually smooth and without nodules. 3. Urinalysis: malignant cysts may feel difficulty in urination and the urine discharged is mixed with blood; benign cysts usually do not show the above reaction. Patients who find cysts on the kidney are recommended to go to regular hospitals in time and receive standardized treatment under the guidance of doctors.