See a dermatologist. The best treatment for a biopsy proven basal cell carcinoma (bcc) is to have it surgically removed. However, bccs come in various subtypes from mild to more aggressive, and it it important to choose the best treatment. For areas on the head and neck , and cosmetically sensitive areas see an acms fellowdhip trained mohs surgeon. Visit http://www.Skincancermohssurgery.Org/ for more information.
Get a biopsy. If you have a suspicious skin lesion that hasn't healed, then you should have a biopsy done. Most primary care doctors or specialists can do a biopsy. For treatment of a confirmed skin cancer you probably should see a dermatologic surgeon or a plastic surgeon who does skin cancer work.
Specialist. If its already diagnosed, you should see a specialist. Some insurance companies may require a referral from your primary in order to see a dermatologist. Check in with your insurance company.