Kidney cancer in its early stages generally does not metastasize. If it does metastasize, it usually follows several paths: one is hematogenous or lymphatic spread, followed by local diffusion, and then the tumor invades surrounding fat or blood vessels, which is local diffusion. It is also important to note that there is a pseudo-capsule around the kidney cancer that prevents the spread of cancer cells. Metastasis is not likely when the tumor is small, but as the tumor size increases or in some special types of tumor cells, metastasis may occur.