It maybe a cyst also. I suggest to come back again to his doctor and tell about spreading cyst on his penis. So that the doctor prescribe medicine to cure the cyst.
I am not sure if they are cysts though? The doctor said one of them was but I a not sure.
cysts do happen from time to time, and they're not normally treated until they become problematic, if they ever do. Three cysts on the penis is worth a revisit to the doctor. Make an appointment.