Is it normal for testicle cysts to never go away?

Hello,

I found a pea sized lump on left testicle about 6 years ago now. Went to the GP, got sent to the hospital for a scan and they said it was nothing bad. Didn’t specify it was a cyst either but if it was cancer then surely it would show up on the machine and he wouldn’t have said that it was nothing. 

The lump is still there. Hasn’t grown or anything and still aches a little after examining. A second lump on the right testicle also appeared on the right testicle about a year after that appointment but hasn’t given me any problems. 

The point is, do cysts go away on their  own? Because it’s been 6 years and the one on the left side hasn’t. 

Thank you.