Common Skin Cancer Symptoms

Regular self-exams can help you catch skin cancer early.

Close up of skin cancer
Callista Images / Getty Images

Skin cancer symptoms can include many different shapes, sizes, and colors of skin lesions, or no visible lesions at all. Some lesions may not even be cancerous or may be related to another medical condition. It is also important to remember that skin cancer—including basal cell carcinoma, squamous cell carcinoma, and melanoma— can appear anywhere on the body, even on areas that are not exposed to the sun, and can occur in people of any race or skin color.

Diagnosing Skin Cancer

Diagnosing skin cancer is not as straightforward as you might think. If skin cancer runs in your family, you should see a dermatologist and check your skin regularly. In general, you should look for these signs during your regular skin self-exam:

  • A new, possibly large, irregularly shaped, dark brownish spot with darker or black areas.
  • A simple mole that changes in color (turning darker), size (growing), or texture (becoming firmer), or flakes or bleeds.
  • A suspicious change in an existing mole or spot.
  • A lesion with an irregular border and red, white, blue, gray, or bluish-black areas or spots.
  • Shiny, firm, dome-shaped bumps anywhere on the body.
  • Dark lesions under the fingernails or toenails, on the palms, soles, tips of fingers and toes, or on mucous membranes (the skin that lines the mouth, nose, vagina, and anus).
  • A sore that doesn't heal within two weeks.

Looking at pictures of basal cell carcinoma, squamous cell carcinoma, and melanoma can help you decide if what you are seeing is a harmless mole (or nevus), a pre-cancerous skin lesion, or something more serious that needs to be analyzed by a dermatologist.

Early Detection of Melanoma

The earlier melanoma is detected, the better your chance of being treated successfully. Monthly self-examinations can help you detect skin cancer early. Often, the first sign of melanoma is a change in the size, shape, or color of an existing mole. It also may appear as a new or abnormal-looking mole.

Use the "ABCDE" rule to help you remember what to watch for:

Asymmetry: The shape of half of the mole does not match the other.

Border: The edges are ragged, notched, or blurred.

Color: The color is often uneven and may include shades of black, brown, and tan. Areas of white, gray, red, or blue may also be seen.

Diameter: The diameter is usually larger than six millimeters (the size of a pencil eraser) or has grown in size.

Evolving: The mole has been changing in size, shape, color, appearance, or growing in an area of previously normal skin. Also, when melanoma develops in an existing mole, the texture of the mole may change and become hard, lumpy, or scaly. Although the skin may feel different and may itch, ooze, or bleed, melanoma usually does not cause pain.

Sometimes, the letter "F" is added, for "funny looking." This is meant to highlight that you should look for moles that do not resemble other moles on your body or moles increasing in size or changing color.

If you see this happening to one of your moles, contact your doctor promptly. A dermatologist can help you determine whether or not your moles are cause for concern. Often, a diagnosis can only accurately be made after your lesion is removed and examined (​biopsied).

A dermatologist can usually remove the mole, or a portion of your skin, in their office with a local anesthetic. 


  • "Melanoma – Treatment Guidelines for Patients." National Comprehensive Cancer Network and the American Cancer Society. 21 July 2008.
  • "What You Need to Know about Skin Cancer." National Cancer Institute. July 2002. 21 July 2008.
  • "All About Skin Cancer – Melanoma." American Cancer Society. July 2008. 22 July 2008.