- Skin Cancer Prevention and Early Detection
- What is skin cancer?
- What is ultraviolet (UV) radiation?
- Are some people more likely to get sun damage?
- How do I protect myself from UV rays?
- What about tanning pills and other tanning products?
- Skin exams
- What should I look for?
- What if I find something suspicious?
- Additional resources
What should I look for?
Skin cancers can show up in many shapes and sizes. Be sure to show your doctor any areas that concern you, especially if they have just appeared or have changed recently.
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 anywhere on the body. Look for new growths, spots, bumps, patches, or sores that don’t heal after several weeks. Shaving cuts that don’t heal in few days sometimes turn out to be skin cancers, which often bleed easily. (They are not caused by shaving.)
Basal cell carcinomas often look like flat, firm, pale areas or small, raised, pink or red, translucent, shiny, pearly bumps that may bleed after a minor injury. They may have one or more abnormal blood vessels, a lower area in their center, and 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’s sometimes a pre-cancer and is caused by too much sun exposure. Actinic keratoses are usually small (less than ¼ inch across), rough or scaly spots that may be pink-red or flesh-colored. Usually they start on the face, ears, backs of the hands, and arms, but they can occur on other sun-exposed areas of 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. These areas should be looked at by a doctor, who can help decide if they should be treated.
Moles and melanomas
A normal mole is usually 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 generally less than 6 millimeters (about ¼ inch) across (about the width of a pencil eraser). A mole can be present at birth, or it can appear during childhood or young adulthood. New moles that appear later in life should be checked by a doctor.
Once a mole has developed, it will usually stay the same size, shape, and color for many years. Some moles may fade away with age.
Most people have moles, and almost all moles are harmless. But it’s important to notice changes in a mole – such as in its size, shape, or color – because this may be a sign that melanoma is developing.
Possible signs and symptoms of melanoma
The most important warning sign for melanoma is a new spot on the skin or a spot that’s changing in size, shape, or color. Another important sign is a spot that looks different from all of the other spots on your skin. If you have any of these warning signs, have your skin checked by a doctor.
The ABCDE rule is another guide to the usual signs of melanoma. Be on the lookout and tell your doctor about spots that have any of the following features:
- 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.
- D is 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.
- E is for Evolving: The mole is changing in size, shape, or color.
Some melanomas do not fit the rules described above, so it’s important to tell your doctor about any changes or new spots on the skin, or growths that look different from the rest of your moles.
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
Last Medical Review: 12/11/2013
Last Revised: 02/20/2014