Talk to Urologist on Testicle Lumps

There are lumps (Hard ones) on the testicles . There are only two lumps which are not visible but once you feel the skin , you can easily make out that there is something hard lump on a testicle . please help if you could they are small in size and never grow. Their size is constant they are of a size of rice grain its been more than 2 years that those are present