If the doctor suspects that a spot on the skin is melanoma skin cancer, the patient will need to have a biopsy. A biopsy is the only way to make a definite melanoma diagnosis. In this procedure, the doctor tries to remove all of the suspicious-looking growth. This is an excisional biopsy. If the growth is too large to be removed entirely, the doctor removes a sample of the tissue. The doctor will never "shave off" or cauterize a growth that might be melanoma skin cancer.
A biopsy can usually be done in the doctor’s office using local anesthesia. A pathologist then examines the tissue under a microscope to check for cancer cells. Sometimes it is helpful for more than one pathologist to check the tissue for cancer cells.