Polycystic kidney. Longitudinal section through a human kidney containing multiple cysts. A ruler gives scale (in centimetres). The normal structure of the kidney has been completely destroyed by the large cysts. Cysts on the kidneys, otherwise known as polycystic disease, is a common cause of kidney failure. The kidney enlarges as its surface becomes studded with cysts. The cysts grow until most of the kidney tissue is destroyed. Polycystic disease is an inherited disorder, treated by dialysis and kidney transplant.