First, the sites of the disease are different; renal pelvis cancer usually occurs in the epithelium of the renal pelvis or calyces, while renal cancer typically originates from the epithelial cells of the renal tubules. Second, the presentations are different; hematuria is a common symptom of both renal pelvis cancer and renal cancer. However, in renal pelvis cancer, hematuria can occur early, while in renal cancer, hematuria may not be seen until the tumor has invaded the renal pelvis or calyces. Third, the diagnostic tests are different; the clinical diagnosis of renal cancer heavily relies on CT scans, whereas renal pelvis cancer primarily depends on excretory or retrograde urography, that is, CT urography. Fourth, the CT appearances are different; on CT scans, renal cancer typically shows as a multicystic lesion with more pronounced enhancement during contrast than that seen in renal pelvis cancer. Fifth, the results of cytological examinations are different; cytology of renal pelvis cancer may show positive tumor cells, but renal cancer might test negative.