Tumours

The kidneys are part of the urinary system. There are 2 kidneys in the body, one on either side of the spine under the lower ribs, deep inside the upper part of the abdomen. The ureters are thin tubes that connect each kidney to the bladder. They are about 25–30 cm long. The urethra is a small tube that connects the bladder to the outside of the body. There is an adrenal gland just above each kidney. The adrenal glands are part of the endocrine system.

The main function of the kidneys is to filter water, impurities and wastes from the blood.

• The blood from the body enters the kidneys through the renal arteries. Once in the kidney, the blood passes through the nephrons, where waste products and extra water are removed. The clean blood is returned to the body through the renal veins.
• The waste products filtered from the blood are then concentrated into urine. The urine is collected in the renal pelvis. The ureters move the urine to the bladder, where it is stored. Urine is passed out of the bladder and the body through the urethra.
• The kidneys also act as endocrine glands. They make these hormones:
  • Erythropoietin (EPO) stimulates the bone marrow to make red blood cells.
  • Calcitriol, a form of vitamin D, helps the colon absorb calcium from the diet.
  • Renin helps control blood pressure.

Kidney cancer is also referred to as renal cell carcinoma (RCC). In the early stages RCC frequently causes no symptoms.  Eventually signs and symptoms may develop and include:

• fatigue,
• weight loss,
• constant back pain,
• a mass or lump on the lower back or side,
• blood in the urine (hematuria),
• anemia (low red blood cell counts), and
• intermittent fevers.