How is skin cancer diagnosed?

Skin cancer is diagnosed starting with a visual exam by a healthcare professional. If you're 40 or older, you should have your provider perform a total body scan every year to look for any signs of skin cancer. If you're younger, you should get a body scan every three years. You also should examine your own skin periodically.

There are several types of skin biopsies that healthcare professionals may perform if you have suspicious-looking growths that could be skin cancer. A skin biopsy involves giving you a local anesthetic and then removing a sample of skin for examination under a microscope. You may feel minor discomfort -- a small needle stick and burning -- for a few seconds. Types of biopsies are as follows:
  • Shave biopsy. The epidermis and the upper part of the dermis are shaved off in a thin slice. This procedure is performed with local anesthesia.
  • Punch biopsy. A sample of the entire thickness of the skin is taken (about 1/8 inch) with an instrument that takes a cylindrical core sample of the skin and a small part of the underlying fat layer.
  • Incisional biopsy and excisional biopsy. With a scalpel, a wider and deeper sample of skin with various amounts of the underlying fat is removed, and then the wound is closed with stitches or staples. Incisional biopsy removes a portion of the growth, and excisional biopsy is used to remove or sample broad or deep growths. 
Dr. Ellen Marmur, MD
Watch as I discuss how skin cancer is diagnosed.
Lori K. Gillespie, MD
Radiation Oncology

The diagnosis of skin cancer often starts after an individual asks their health care provider about a suspicious mark or bump on their skin or after a routine skin examination. The first thing a health care provider will do is inspect the suspicious area. They are looking at the area to determine if it has irregular borders, are asymmetrical, has several different colors, and are looking at the size. After the inspection, the provider may have the area removed and sent away to a laboratory for further testing. At this time, a pathologist will view the sample under a microscope to determine whether or not it is cancer.

If you have a change on the skin, the doctor must find out whether it is due to cancer or to some other cause. Your doctor removes all or part of the area that does not look normal. The sample goes to a lab. A pathologist checks the sample under a microscope. This is a biopsy. A biopsy is the only sure way to diagnose skin cancer.

You may have the biopsy in a doctor'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.

This answer is based on source information from National Cancer Institute.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.