In most cases, skin cancer is identified first by a doctor as an abnormal area on the skin. However, they won’t know if it’s cancerous or not until it’s removed and tested. This is a biopsy. A biopsy is the only sure way to diagnose skin cancer.

You may have the skin cancer biopsy in a dermatologist’s office or as an outpatient in a clinic or hospital. Where it is done depends on the size and place of the abnormal area on your skin. You probably will have local anesthesia.

There are four common types of skin biopsies:

  • Punch Biopsy: The doctor uses a sharp, hollow tool to remove a circle of tissue from the abnormal area.
  • Incisional Biopsy: The doctor uses a scalpel to remove part of the growth.
  • Excisional Biopsy: The doctor uses a scalpel to remove the entire growth and some tissue around it.
  • Shave Biopsy: The doctor uses a thin, sharp blade to shave off the abnormal growth.

The dermatologist will never “shave off” or cauterize a growth that might be melanoma. An excisional biopsy will be performed, or, if the growth is too large to be removed entirely, a tissue sample will be taken.