Lumps in testicles, help?

Hi. A year or so ago I went to the doctor because I had found tiny hard lumps in both testicles. They were attached to the testicles and weren't very large and were not painful. I am 18, so my doctor was fairly convinced that it wasn't cancer, but referred me to a specialist anyway. The specialist also said that he didn't think it was cancer. He said that it was a condition in which fragments of what would've been the fallopian tube before I had formed as a male and hardened over time. What is this condition called? These lumps are still present and I can't help but worry that he might've been wrong and that it could be cancer. lol Yes, I am paranoid, but still. I can't find any information on a condition like what he said? Perhaps I misunderstood him?