I had a itchy frecle type mole on my shoulder removed a while back biopsy came back negative. But im concerned again as on my back I GT hard itchy sk?

Scar tissue. Over a joint or area of thich skin, you can develop thickened itchy s ar tissue. Bio oil or Mederma may decrease the thickness and relieve the itching. If not see doctor for dilute kenalog (triamcinolone). Injection to soften scar.
Itchy skin . If you are having itchy skin at the biopsy site it could be part of the healing process and subsequent scar formation (depending on when the removal occurred . Since the condition is not improving see your dermatologist to make sure the area is ok and not more serious.