The structures of kidney cysts can be different from each other and there are four different types. There is a kidney cyst. The tendency of kidney cysts to become cancerous varies depending on the structure of the cyst. The first type of cysts are simple cysts and do not turn into cancer. The probability of second type cysts turning into cancer is around 5%. For this reason, cysts must be kept under control at regular intervals. The risk of third type cysts turning into cancer is 50%. That's why cysts need to be removed from the body. The fourth type of cyst is considered a tumor and must be removed from the body immediately.