What Does Skin Cancer Look Like? Signs and Symptoms

Is that irritating skin tag under your arm actually cancer? Or what about that persistent rash under your breasts? What does skin cancer look like?

Skin cancers range from being easy-to-spot to being notoriously difficult to identify. Read on to learn what different skin cancers typically look like, where you need to check for them, and what the early warning signs are.

What is skin cancer?

Skin cancer is the abnormal or unregulated growth of skin cells. There are two main types of skin cancer: melanomas and non-melanoma skin cancers. The non-melanoma skin cancers can be further divided into basal cell carcinomas (BCC) and squamous cell carcinomas (SCC).

Skin cancers are usually named according to the cells in which they originate. Melanomas have their origin in melanocytes, which are the melanin-producing cells of the skin. Melanin is the pigment that gives skin its color. BCCs develop in the basal cells and SCCs in the squamous cells.

Let’s take a deeper look at the characteristics, signs, and symptoms of different skin cancers.

Basal cell carcinoma

Basal cell carcinoma (BCC) is the most common skin cancer in the U.S¹. BCC lesions usually occur in sun-exposed areas of the body, such as the scalp, neck, face, ears, lips, nose, shoulders, neck, and back; however, they can occur anywhere on the body.

There are five useful warning signs to look out for if you find a new or concerning skin lesion:

1. A skin lesion that refuses to heal or that consistently oozes or crusts over. Sometimes the sore may appear to heal, but after a short while, it reappears again.

2. A reddish, irritated patch that may itch, scale, hurt or even cause no discomfort at all. Often these will be on sun-exposed areas, such as your chest, back, or arms.

3. A shiny bump or nodule that may be pearly, clear, pink, red, or tan.

4. A pink or pearly nodule with a rolled, raised edge, and a central indentation that may ulcerate or crust. Tiny blood vessels may develop on the surface of the lesion.

5. A scar-like area that may be white or yellow in color. Usually, the borders are ill-defined and the skin appears shiny and taut. This is an important warning sign because it may indicate that the BCC has spread locally into the surrounding tissue.

If two or more of these signs are present, there’s a good chance that the lesion you are looking at is a BCC.

Squamous cell carcinoma

Squamous cell carcinoma is the second most common skin cancer in America². It is generally slow-growing cancer that spreads locally before metastasizing. Only about 2–5% of SCC³ will grow back or spread after treatment.

SCC is usually found on very sun-exposed body parts. The lesions are typically seen on the face, lips, ears, neck, back of the hand, and forearm. SCC can also develop in old scars, where it may be difficult to see. Rarely, SCC can develop in the anus, vulva, nails, and mouth.

• SCC often looks like a rough, scaly patch or plaque, occasionally with a raised border and “collapsed” central appearance.

• Color may vary between red, pink, white, and brown.

• The lesion can be crusty or flaky.

• SCC may sometimes have the appearance of a wart or verruca-like lesion. This type of SCC tends to occur on the foot, on the genitals, or in the mouth.

• A warning sign that a lesion may be an SCC is if it bleeds easily or frequently and does not heal as you would expect it to.

Actinic keratosis is a precancerous lesion that often looks very similar to SCC. If Actinic keratoses are treated, they will resolve completely; however, if they are ignored, they will eventually develop into SCC.

Melanoma

Melanomas can develop spontaneously on previously normal skin or within an existing mole. It’s for this reason that it’s important that you keep an eye on the appearance of your moles.

They most commonly occur in areas of the body that have been exposed to the sun, such as the back, neck, legs, arms, and face.

Melanomas can also occur in areas of your body that aren’t exposed to the sun. This is more commonly the case in people who have darker skin, such as people of Asian or African American descent.

As well as sun-exposed areas, you should check for melanomas on the soles of your feet, the palms of your hands, and your fingernail beds. Melanomas in these places are called acral-lentiginous melanomas.

Occasionally, melanomas can occur in the inside of the mouth, anus, vagina, or eye, but these are more rare and difficult to detect.

How to differentiate between a normal mole and a melanoma

Benign moles usually appear on the skin between the ages of ten and 40. It is unusual to develop new moles after the age of 40.

Normal moles are usually well-defined, round, or oval shapes with a regular border that separates the mole from the surrounding skin. The mole should be uniform in color and have a diameter smaller than a quarter of an inch.

Melanomas can be distinguished from moles using the ABCDE method:

• A is for asymmetrical: the lesion has an irregular shape or two different sized halves.

• B is for an irregular border: the border of the mole is irregular and poorly defined.

• C is for color: the color of the lesion is blotchy and uneven. It may be a combination of different shades of red, black, brown, white, or blue.

• D is for diameter: a mole that grows larger than 6mm in diameter has a high chance of being a melanoma.

• E is for evolving: watch for moles that change with time. This may be a change in any of the ABCD characteristics or may even be that the mole starts becoming itchy or bleeds easily on contact.

If any of these ABCDE characteristics are present, you need to see a dermatologist to get your lesion checked out.

The “ugly duckling” method

Another method that is commonly used by dermatologists to identify melanomas is nicknamed the “ugly duckling” method. You will remember that the ugly duckling looked different from all the other ducklings in the group. The same principle applies to moles.

Most people will have specific characteristics to their moles depending on their genes, skin type, etc. Moles that look different from all your other moles should be a warning sign that they may be melanomas.

Getting to “know” your usual moles and checking for the ugly duckling, or odd, moles can help you to pick up melanomas early.

What isn’t skin cancer?

The only way to be 100% sure that a lesion is not cancerous is to have it removed or biopsied and to have a pathologist look at the histology of the tissue.

However, the following are unlikely to be malignant and can usually just be monitored:

• Typical skin tags—these are usually found in areas of the body that rub against each other, such as under the arms or breasts.

• Freckles that have been present since childhood—these are small, flat, pigmented lesions that have been present since a young age and that usually fade without sun exposure. Use the ABCDE method to monitor them.

• Age spots—also called liver spots or solar lentigines. These are common in people over the age of 50 but may also be present in younger people who have spent a lot of time in the sun. They are typically present on areas of skin that have been exposed to the sun or that are sun-damaged. They can co-exist with skin cancers. Use the ABCDE approach to monitor age spots for malignant change.

Features of solar lentigines (age spots):

• Flat, oval areas of increased pigmentation

• Usually tan to dark brown

• Occur on skin that has had the most sun exposure over the years, such as the backs of hands, tops of feet, face, shoulders, and upper back

• Range from freckle size to about 1/2 inch (13mm) across

• Can group together, making them more noticeable

Why is it important to identify skin cancer early?

The vast majority of skin cancer is completely curable if it is caught early⁴. When diagnosis and treatment of skin cancer are delayed, the risk of death increases significantly. This is especially true of melanomas. Compared with early-stage melanoma patients, treated within 30 days of being biopsied, those treated 30 to 59 days after biopsy have a 5% higher risk of dying from the disease, and those treated more than 119 days after biopsy have a 41% higher risk.

The easiest way to identify skin cancer early is to examine your skin regularly for any new or changing lesions. Remember to check your whole body. If you find any suspicious spots, make an appointment to see your doctor. Some people like to make regular annual or six-monthly skin screening appointments with their dermatologists.

Many dermatologists offer mole-mapping, which is a specialized, ongoing form of screening moles for malignant changes.

Whatever way you choose to check your skin, remember that early detection of skin cancer could save your life.