A doctor inspects a suspicious mole on the back of a woman; how to identify skin cancer concept
Image Point Fr/Shutterstock.com

Did you know that the most common form of cancer in the United States is skin cancer? According to experts, roughly 1 in 5 people in this country will develop skin cancer at some point during their lifetime. In other words, about 20% of people in the United States will develop this condition, making the need for identifying skin cancer warning signs important.

How to Identify Skin Cancer Warning Signs

Anyone who suspects they have any form of cancer should seek medical attention right away.

The 3 basic forms of skin cancer are basal cell carcinoma (BCC), malignant melanoma (melanoma), and squamous cell cancer (SCC). Which symptoms are present can depend on the type of skin cancer the person has, although there can be some overlapping signs. So, just what are the common signs that someone has developed the most common form of cancer in the US?…

10. White Waxy Lumps

Basal cell carcinoma under the nose of a pale-skinned man
SkarmoutsosV (CC BY-SA 4.0)

According to the CDC, changes in skin are the most recognizable symptoms of cancer of the skin. One such change is the appearance of white, waxy-looking lumps on the skin.

What do the lumps look and feel like?

These bumps can look a little different, depending the individual, their skin tone, and the stage of cancer that they’re at. However, these lumps might indicate cancer if they:

  • Are white or yellow in color
  • Have a waxy appearance
  • Have no clearly defined border
  • Look similar to a scar
  • Are flat
  • Feel firm

What type of cancer is it?

These peculiar lumps can indicate non-melanoma skin cancer, specifically BCC.

9. Brown Scaly Patch

Actinic keratosis seen on the back of the hands
James Heilman, MD (CC BY-SA 4.0)

The technical term for these darkly colored splotches of skin are actinic keratosis (AK), or solar keratosis. While they themselves are not initially cancerous, they have the potential to become cancerous.

What are AKs?

These pre-cancerous growths can be:

  • Scaly, rough, and/or dry
  • Range in color from reddish/pinkish to brown
  • Crusty or bleed easily

What type of cancer is it?

AKs have the potential to develop into non-melanoma cancer, specifically SCC.

8. Mole Changes

This photograph, produced by the Skin Cancer Foundation, and made available by the National Cancer Institute (NCI), depicts a close view of a dermatology patient’s skin surface, revealing the presence of brown pigmented lesion, which was diagnosed as melanoma. This lesion exhibited a heterogeneous, mottled pigmentation, ranging from light tan, to dark brown, and is very asymmetrical, with a highly irregular border. All these characteristics should raise the suspicions of a qualified dermatologist, as to the melanomatous nature of this lesion. Use of this image requires acknowledgement that NCI is the image source, as well as the inclusion of the website, www.cancer.gov.
National Cancer Institute (NCI), www.cancer.gov

People who already have moles and notice abnormal changes should practice caution and seek medical attention, as these changes could indicate cancer.

What changes indicate cancer?

Experts have created a handy way to quickly assess if mole changes are likely to be cancerous: ABCDE.

  • Asymmetry – Does the mole look asymmetrical? Are there different areas of this skin patch that look dissimilar?
  • Border – Are there changes to the border of the mole? Is it becoming “jagged”?
  • Color – Is the mole changing color? Are these color changes uneven?
  • Diameter – Is the mole growing? Does it now exceed the size of a pea?
  • Evolving – Is the mole evolving or has evolved noticeably within the past few months or weeks?

What type of cancer is it?

ABCDE changes typically indicate melanoma, which experts typically consider to be more serious than non-melanoma cancers.

7. Wart-like Growths

This photograph, created by Kelly Nelson, and made available by the National Cancer Institute (NCI), depicts a close view of the skin of a dermatology patient's right temple, revealing the presence of an asymmetrical, crusty raised lesion, which was determined to be a case of skin cancer known as squamous cell carcinoma. Use of this image requires acknowledgement that NCI is the image source, as well as the inclusion of the website, www.cancer.gov.
Kelly Nelson, National Cancer Institute (NCI); www.cancer.gov

When new lumps and spots appear on the skin, it’s time for closer inspection.

What are these growths like?

This particular cancer symptom can present as:

  • Rough and thick
  • Like a wart
  • Crusty and/or bleeding

What type of cancer is it?

Experts typically associate these growths with SCC, a non-melanoma cancer.

6. Open, Unhealing Sores

Pathology: Patient: Squamous Cell Carcinoma Description: Tends to arise from pre-malignant lesions, actinic keratoses; surface is usually scaley and often ulcerates (as shown here). Subjects (names): Topics/Categories: Pathology -- Patient Type: Color Slide Source: National Cancer Institute Author: Unknown photographer/artist AV Number: AV-8500-3609
National Cancer Institute

Everyone experiences bumps and bruises. When these injuries fail to heal properly, an underlying medical condition could be to blame.

What are these sores like?

When someone notices new, open sores that never seem to heal, heal incredibly slowly, or keep coming back, cancer could be to blame. Further, these sores may ooze and eventually crust over, giving them a crusty appearance.

What type of cancer is it?

These sores typically indicate SCC and BCC, both of which are non-melanoma cancers.

5. Rough, Scaly Red Patches

This photograph, made available by the Dermatology Branch of the National Cancer Institute (NCI), depicts a close view of a dermatology patient’s skin, revealing the presence of a flat, mottled red spot that was rough, dry, and scaly. These characteristics warranted further scrutiny by a qualified dermatologist, in order to make a determination, as to whether this lesion was precancerous, or had evolved into a frank form of skin cancer. Use of this image requires acknowledgement that NCI is the image source, as well as the inclusion of the website, www.cancer.gov.
Dermatology Branch; National Cancer Institute; www.cancer.gov

Red patches are common indicators of many medical conditions, ranging from bug bites to cancer.

What are these patches like?

While it can be hard to distinguish these patches from other dermatologic conditions, cancerous swatches of skin tend to be:

  • Rough and scaly
  • Reddish in color
  • Crusty
  • Bleeding

What type of cancer is it?

These red patches are usually indicative of non-melanoma cancer.

4. New Lumps or Other Abnormal Growths

This photograph, created by Kelly Nelson, and made available by the National Cancer Institute (NCI), depicts a close view of the skin of a dermatology patient's lower leg, revealing the presence of an asymmetrical, raised red lesion, which was determined to be a case of skin cancer known as squamous cell carcinoma. Use of this image requires acknowledgement that NCI is the image source, as well as the inclusion of the website, www.cancer.gov.
Kelly Nelson, National Cancer Institute (NCI); www.cancer.gov

Any time a new growth appears, it’s time to take a closer look.

What do cancerous lumps look and feel like?

Once again, it can be hard to distinguish these growths from other skin conditions. However, cancerous skin growths tend to be:

  • Lumpy or raised
  • Sometimes raised along the edges with a dip in the interior
  • Can feel incredibly tender or have a rough surface
  • May be fragile and ooze or bleed upon contact

What type of cancer is it?

These growths are common in cases of SCC.

3. Pink Growths

Nodular basal cell carcinoma; red bumped with raised edges
Unchanged from © DermNet New Zealand (CC BY-NC-ND 3.0 NZ)

This symptom can look similar to other skin conditions, which means concerned individuals will have to closely inspect suspicious growths and consult a licensed medical provider.

What are these growths like?

Distinctively cancerous pink growths can:

What type of cancer is it?

This particular type of growth is seen with BCC.

2. Eye Changes

Collage image of ocular melanoma
Left – Jonathan Trobe, M.D. – University of Michigan Kellogg Eye Center (CC BY 3.0). Right – Maliflower73/Shutterstock.com

The neck, face, and arms are all common locations for skin cancer to develop. In rare cases, though, skin cancer can develop in the eyes.

What are these changes like?

Skin cancer-related eye changes include:

  • Partial vision loss
  • Blurry vision
  • Dark spots in the iris, the colored part of the eye surrounding the pupil
  • Dark spots in the conjunctiva (mucus membrane that lines the eyelids) or whites of the eye

What type of cancer is it?

These changes can indicate eye melanoma, or ocular melanoma. Two major types of this cancer are uveal melanoma and conjunctival melanoma.

1. Ugly Ducklings

This photograph, produced by the Skin Cancer Foundation, and made available by the National Cancer Institute (NCI), depicts a close view of a dermatology patient’s skin surface, revealing the presence of an asymmetrical, dark-brown pigmented lesion, which was diagnosed as melanoma. Note that the left half of this lesion is much thicker than its right. This asymmetry should be a warning sign to an experienced dermatologist. The thickness, in and of itself, is a danger sign, for it could indicate that the lesion’s depth now includes the dermis, below the outer epidermal layer. These features could indicate a possible melanomatous lesion. Use of this image requires acknowledgement that NCI is the image source, as well as the inclusion of the website, www.cancer.gov.
Skin Cancer Foundation; www.cancer.gov

The ugly duckling isn’t just a nursery rhyme character, but also a term experts use to define one standout symptom of skin cancer.

What is an “ugly duckling”?

An ugly duckling is, as the name implies, an odd patch of skin that does not look like other moles or freckles. In other words, it is a patch of skin that looks odd.

What type of cancer is it?

Like the ABCDE method, the “ugly duckling sign” can indicate melanoma.

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

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