Left kidney tumors are not necessarily malignant, such as renal malformation tumor, renal cyst, renal fibroma, etc. are all benign kidney tumors. The morphology of benign tumors is more regular, and most of them have a complete envelope, and they do not invade the surrounding normal tissues and structures. On the other hand, malignant tumors are usually not very regular in shape and grow in a crabfoot-like infiltration around. Sometimes, in order to further diagnose the benignity and malignancy of kidney tumor, CT or even enhanced CT is needed to confirm the diagnosis. If the kidney tumor cannot be identified as benign or malignant, it can be diagnosed by puncture biopsy or surgical resection for rapid pathology.