Examining your skin
Get your skin checked by your doctor

As part of a routine cancer-related checkup, your doctor should check your skin carefully. He or she should be willing to discuss any concerns you might have about this exam.

How to check your own skin

It's important to check your own skin, preferably once a month. A self-exam is best done in a well-lit room in front of a full-length mirror. You can use a hand-held mirror for areas that are hard to see. A spouse or close friend or family member may be able to help you with these exams, especially for those hard-to-see areas like the lower back or the back of your thighs.

The first time you inspect your skin, spend a fair amount of time carefully going over the entire surface of your skin. Learn the pattern of moles, blemishes, freckles, and other marks on your skin so that you'll notice any changes next time. Any trouble spots should be seen by a doctor. Follow these step-by-step instructions to examine your skin:

Face the mirror:

What should I look for?

Basal and squamous cell cancers

Basal cell cancers and squamous cell cancers are most often found in areas that get exposed to a lot of sun, such as the head, neck, and arms, but they can occur elsewhere. Look for new growths, spots, bumps, patches, or sores that don't heal after 2 to 3 months.

Basal cell carcinomas often look like flat, firm, pale areas or small, raised, pink or red, translucent, shiny, waxy areas that may bleed after a minor injury. They may have one or more abnormal blood vessels, a lower area in their center, and/or blue, brown, or black areas. Large basal cell carcinomas may have oozing or crusted areas.

Squamous cell carcinomas may look like growing lumps, often with a rough, scaly, or crusted surface. They may also look like flat reddish patches in the skin that grow slowly.

Both of these types of skin cancer may develop as a flat area showing only slight changes from normal skin.

Actinic keratosis, also known as solar keratosis, is a skin condition that is sometimes pre-cancerous and is caused by too much sun exposure. Actinic keratoses are usually small (less than ¼ inch), rough spots that may be pink-red or flesh-colored. Usually they develop on the face, ears, back of the hands, and arms of middle-aged or older people with fair skin, although they can arise in younger people or on other sun-exposed areas of the skin. People with one actinic keratosis usually develop many more. Some can grow into squamous cell cancers, but others may stay the same or even go away on their own. Because they can turn cancerous, such areas should be looked at regularly by a doctor. Your doctor can then decide whether these areas should be removed.

Melanomas

The "ABCD rule" is an easy guide to the usual signs of melanoma. Be on the lookout and tell your doctor about any spots that match the following description:

• A is for ASYMMETRY: One half of a mole or birthmark does not match the other.
• B is for BORDER: The edges are irregular, ragged, notched, or blurred.
• C is for COLOR: The color is not the same all over and may include shades of brown or black, or sometimes with patches of pink, red, white, or blue.
• Dis for DIAMETER: The spot is larger than 6 millimeters across (about ¼ inch — the size of a pencil eraser), although melanomas can sometimes be smaller than this.

Another very important sign of possible melanoma is a change in the size, shape, or color of a mole or the appearance of a new spot. Some melanomas do not fit the ABCD rule described above, so it is very important to tell your doctor about any changes in skin markings or new spots on your skin.

Other warning signs are:

• a sore that does not heal
• spread of pigment from the border of a spot to surrounding skin
• redness or a new swelling beyond the border
• change in sensation — itchiness, tenderness, or pain
• change in the surface of a mole — scaliness, oozing, bleeding, or the appearance of a bump or nodule
• a mole that looks very different from your other moles

What if I find something suspicious?

It's important to know the difference between melanoma and a harmless mole. A normal mole is most often an evenly colored brown, tan, or black spot on the skin. It can be either flat or raised. It can be round or oval. Moles are usually less than 1/4 inch across, or about the width of a pencil eraser. Moles can be present at birth or they can appear later. Several moles can appear at the same time.

Once a mole has developed, it will usually stay the same size, shape, and color for many years. Moles may fade away in older people.

Most people have moles, and almost all moles are harmless. But it is important to recognize changes in a mole — such as its size, shape, or color — that suggest a melanoma may be developing.

Be sure to show your doctor any area that concerns you. A qualified doctor should be able to identify any suspicious areas you may have. If your doctor suspects you might have skin cancer, he or she will use one or more of the following methods to find out.

History and physical exam

Usually the first step is to take your medical history (ask questions about symptoms and risk factors). The doctor probably will ask your age, when the mark on the skin first appeared, and if it has changed in size or appearance. You may also be asked about past exposures to known causes of skin cancer and if you or anyone in your family has had skin cancer.

During your physical exam, your doctor will note the size, shape, color, and texture of the area in question, and if there is bleeding or scaling. The rest of your body may be checked for spots and moles that may be related to skin cancer.

The doctor may also feel the lymph nodes (bean-sized collections of immune system cells) under the skin near the suspicious area. Some skin cancers may spread to lymph nodes. Affected lymph nodes may become larger and firmer than usual.

If you are being seen by your primary doctor and skin cancer is suspected, you may be referred to a dermatologist (a doctor who specializes in skin diseases), who will look at the area more closely.

Along with a standard physical exam, many dermatologists use dermoscopy (also known as epiluminescence microscopy (ELM), surface microscopy, or dermatoscopy) to help determine if a spot might be a melanoma or other type of skin cancer. This involves the use of a dermatoscope, which is a special magnifying lens and light source held near the skin. Sometimes the doctor will use a thin layer of oil with this instrument. A digital or photographic image of the spot may be taken. The use of these tests by experienced dermatologists can improve accuracy in finding skin cancers early. It can also often reassure you that a lesion is benign (non-cancerous) without the need for a biopsy.

Skin biopsy

If the doctor thinks that an area of skin might be cancerous, he or she will take a sample of skin from that area to look at under a microscope. This is called a skin biopsy. Different methods can be used for a skin biopsy. The choice of method depends on the possible type of skin cancer, where it is on the body, and the size of the affected area. For more detailed information on biopsies, see our documents, Melanoma Skin Cancer and Skin Cancer: Basal and Squamous Cell.

If a spot is found to be cancerous or pre-cancerous, your doctor may recommend further tests or treatment. If the spot is small and localized, a more extensive biopsy or some type of surgery may be needed. For cancers that might be more extensive (especially melanomas), imaging tests might be done, and treatment might include chemotherapy or radiation. Again, for more detailed information, see our skin cancer documents.

Last Medical Review: 06/11/08
Last Revised: 06/11/08

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