A physician will perform a biopsy if he or she determines a skin lesion is consistent with the warning signs of cancer. During the biopsy, a sample of tissue is removed for examination to determine if the tissue cells are benign (normal), atypical (abnormal), or cancerous. The specimen is often sent to a lab and examined by a pathologist under a microscope to make this determination. Most biopsies are done under local anesthetic, in the physician's office, at the time of the skin examination.