i have some hard lumps on my scrotum (upper part) from years

i have some hard lumps on my scrotum (upper part) from years its constant no size increase or decrease i have no pain i have tried to squeeze it (thinking its lyk pus) but no it wasn't there's nothing lyk pain or anything i have to bother about. its just on my skin nothing else but seeing some post in steadyhealth.com i was little scared and want to ask whats dis. is it a cyst. and do i have to do anything for that enclosed pic (http://anuragdeb3.net63.net/SAM_0700.JPG)