Renal cancer is a malignant tumor originating from the urinary tubular epithelial system of the renal parenchyma. The full academic term is renal cell carcinoma, also known as renal adenocarcinoma, or simply renal cancer. It includes various subtypes of renal cell carcinoma originating from different parts of the urinary tubules, but excludes tumors originating from the renal interstitium and renal pelvis tumors. The etiology of kidney cancer is unknown. The factors related to the development of kidney cancer are genetics, smoking, obesity, hypertension and anti-hypertensive treatment. In recent years, most kidney cancer patients are asymptomatic kidney cancer discovered during health check-ups, and these patients account for more than 50% to 60% of the total number of kidney cancer patients. The most common symptoms among symptomatic kidney cancer patients are lumbar pain and hematuria, and a few patients come to the hospital with abdominal masses. 10% to 40% of patients have paraneoplastic syndrome, which manifests as hypertension, anemia, weight loss, cachexia, fever, erythrocytosis, abnormal liver function, hypercalcemia, hyperglycemia, increased sedimentation, neuromuscular lesions, amyloidosis, overflow, abnormal coagulation mechanism, etc. 20% to 30% of patients have paraneoplastic syndrome. 20%-30% of patients may visit the doctor due to symptoms such as bone pain, fracture, cough and hemoptysis caused by tumor metastasis. Diagnosis of kidney cancer requires laboratory examination, imaging examination and pathological examination. Treatment principles: Patients with limited or locally progressive (early or middle stage) kidney cancer should be treated mainly by surgery, while metastatic kidney cancer (advanced stage) should be treated by comprehensive treatment mainly by internal medicine. The main purpose of post-treatment follow-up is to check for recurrence, metastasis and neoplastic tumors. For patients who underwent kidney unit preservation surgery, abdominal CT scan should be performed 4-6 weeks after surgery, so that doctors can grasp the changes of kidney morphology after surgery, which can be used for future review for comparison. The contents of follow-up examination include: 1) medical history questioning; 2) physical examination; 3) routine blood and blood biochemical examination, such as liver and kidney function as well as blood biochemical indexes of abnormal preoperative examination; 4) chest X-ray or chest CT scan examination; 5) abdominal ultrasound or/and abdominal CT scan examination. Renal pelvic cancer accounts for about 10% of all renal tumors, and its incidence varies regionally. Most are metastatic epithelial carcinomas, and a few are squamous epithelial carcinomas and adenocarcinomas. Long-term chronic irritation of the renal pelvis, such as stones and inflammation, can sometimes induce squamous epithelial carcinoma or adenocarcinoma of the renal pelvis. Antler-shaped kidney stones have a high complication of metastatic epithelial carcinoma. 30-50% of patients with metastatic epithelial carcinoma of the renal pelvis may also have metastatic epithelial carcinoma of the bladder. If there is a tumor in both the renal pelvis and ureter, the likelihood of developing bladder cancer increases to 75%. The most common symptom of renal pelvis cancer is hematuria. CT is useful to see if the tumor is papillary and broad-based and to clearly differentiate between renal cancer and pelvic cancer. The positive rate of finding cancer cells in the urine is higher for those with higher malignancy. When available, ureteropelvoscopy and brush biopsy are feasible. The treatment of renal pelvis cancer is mainly surgery. Patients with metastatic epithelial carcinoma of the renal pelvis should have the affected kidney removed along with the ureter and the bladder wall around the ureteral orifice. In such patients, if local excision of renal pelvis cancer is performed, nearly 100% of highly malignant cases will recur, and about 50% of low-grade malignant tumors will recur. In addition to radical nephrectomy, all ureters and the bladder wall around the ureteral orifice should be removed for pyel cancer. After surgery, regular bladder irrigation therapy is required to prevent recurrence of bladder tumors. Regular cystoscopy is also required.