Nephron occupying lesions can be divided into benign and malignant occupancies, for example, renal cysts, renal malformations, hemangiomas, and calcified foci are all benign occupancies. Renal cancer and pelvic cancer are malignant occupancies. To distinguish whether a renal occupancy is benign or malignant, CT or MRI enhancement of the kidney is needed to clarify the nature of the occupancy. If the nature of the occupancy cannot be confirmed after CT or MRI examination, a kidney biopsy can be performed to determine whether it is benign or malignant through pathology. Therefore, a renal occupancy is not necessarily cancer.