I have a lump of dead skin on my foreskin . . . the doctor informed me it is harmless and could remove it through surgery . , is it necessary ?

Dead or Discolored?: If in fact you have dead skin, then given the location you should have it removed via circumcision and looked at by a pathologist. Bxo (look up) can discolor it as well. At a minimum you should have a biopsy. If you have patches of lighter skin, then that is often a condition known as vitiligo. That is harmless and a circumcision is elective. A urologist should be able to give you your answer.