Thanks for the query to H.C.M. Forum.
As you mentioned that pea size lump is over the scrotum
and this lump is nothing is to do with testicular cancer
As testicles are lodged in a pouch and scrotum is absolutely on outer side structure.
The pea size lump is a most common thing and this in my opinion is sebaceous cyst
Consult a surgeon and get an excision operation ,hardly 5-10 minute remooval process.