Why are renal pelvis tumors malignant?

Renal pelvis tumor is mainly urothelial tumor, urothelial tumor benign few, most are malignant. Mainly affected by environmental factors, may also be often exposed to some chemicals, or urinary tract stone stimulation caused. Renal pelvis tumor, early symptoms may be macroscopic hematuria, lumbago, may also cause fever of unknown cause, and anemia. After doing ct plain scan and enhancement, ureteroscopy, can be diagnosed renal pelvis tumor. After the diagnosis of renal pelvis tumor, the general should be performed renal pelvis ureter resection surgery. After surgery should be regular review, observe whether there is bladder tumor recurrence.