Skin Cancer Prevention and Early Detection

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What should I look for on a skin self-exam?

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 develop 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 can appear in a number of different ways:

  • Flat, firm, pale or yellow areas, similar to a scar
  • Raised reddish patches that might be itchy
  • Small, pink or red, translucent, shiny, pearly bumps, which might have blue, brown, or black areas
  • Pink growths with raised edges and a lower area in their center, which might contain abnormal blood vessels
  • Open sores (which may have oozing or crusted areas) that don’t heal, or that heal and then come back

Squamous cell carcinomas can appear as:

  • Rough or scaly red patches, which might crust or bleed
  • Raised growths or lumps, sometimes with a lower area in the center
  • Open sores (which may have oozing or crusted areas) that don’t heal, or that heal and then come back
  • Wart-like growths

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 can sometimes progress to squamous cell cancer (although most of them do not).

Actinic keratoses are caused by too much sun exposure. They 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, while others may stay the same or even go away on their own. But it can be hard sometimes even for doctors to tell them apart from true skin cancers. These areas should be looked at by a doctor, who can help decide if they should be treated.

Moles and melanomas

Normal moles

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). Some moles can be present at birth, but most 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 into 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

To see some examples of skin cancers and other skin conditions, visit our Skin Cancer Image Gallery.

Last Medical Review: 03/19/2015
Last Revised: 03/20/2015