Renal smooth muscle lipoma is not cancer, but a benign tumor. Cancer refers to a mass with migratory and metastatic properties, while renal smooth muscle tumor does not have this characteristic. Usually, patients have no obvious symptoms, and in most cases, it is discovered only due to physical examination. Sometimes, patients may have pain in the lower back and hematuria at the same time, which need to be distinguished from kidney cancer when checking ultrasound. If the tumor is larger than 5cm or above, surgery is needed, and in most cases, laparoscopic nephrectomy or partial nephrectomy can be performed, and patients usually recover well after the surgery, with no obvious complications and sequelae, and metastasis will not occur. Regular postoperative follow-ups are required to check the kidneys for obvious bleeding and other complications. After the discovery of the mass, you should not eat too spicy food, such as chili peppers and spicy sticks, or drink alcohol for a short period of time. Appropriately consume more high quality protein with low fat and low cholesterol content, such as fish and shrimp.