Kidney tumors are abnormal growths that can develop in one or both kidneys. They can be benign (non-cancerous) or malignant (cancerous). The most common type of kidney cancer in adults is called renal cell carcinoma. Symptoms may include blood in the urine, persistent back pain, and unexplained weight loss. Diagnosis typically involves imaging tests like CT scans or ultrasounds, and a biopsy may be performed to determine the nature of the tumor. Treatment options vary based on the type and stage of the tumor and may include surgery, radiation therapy, or targeted drug therapy.