Table of ContentsView AllTable of ContentsBasics of Skin CancerTypes of Skin CancerABCDE Rule of Skin CancerWhen to See a Healthcare Provider
Table of ContentsView All
View All
Table of Contents
Basics of Skin Cancer
Types of Skin Cancer
ABCDE Rule of Skin Cancer
When to See a Healthcare Provider
Moles or marks on the skin can be anxiety-producing, and it’s not always easy to remember what to look for when examining moles or growths to see if they may be cancerous.
The ABCDE rule forskin cancercan help. This mnemonic devicehelps outline the physical characteristics of skin abnormalities, which helps determine whether it has cancer features.
Read on to learn more about this easy way to remember what to look for.
1:50Watch Now: The ABCDE Rule of Melanoma
1:50
Watch Now: The ABCDE Rule of Melanoma
The Basics About Skin Cancer
By definition, skin cancer is the abnormal growth of skin cells. Some types of skin cancer can invade deeper layers of the skin or may spread and damage other areas of the body.
The epidermis contains three main types of cells:
The type of cell involved helps your healthcare provider determine the treatment options and the prognosis (likely outcome). The appearance of the skin may provide a clue as to which type of cell is involved, but askin biopsyis needed for a definitive diagnosis.
The ABCDE Rule of Skin Cancer
Checking your skin forchangescan help identify melanoma in its earliest stages. This can increase your chances of successful treatment.
A Is for Asymmetry
Normal moles or freckles are typically symmetrical. If you were to draw a line through the center, you would have two symmetrical halves. In cases of skin cancer, spots will not look the same on both sides.
Remember that shape is only one of the features healthcare providers look for when identifying skin cancer. An irregular-shaped mark does not necessarily mean you have cancer.
B Is for Border
Moles, spots, or “beauty marks" are typically round and of no cause for concern. Those with a blurry and/or jagged edge can be a sign of cancerous or pre-cancerous growth.
C Is for Color
Normal moles and spots are usually one color. A mole that has more than one color should be considered suspicious. Color changes can include the darkening of a spot (sometimes dark purple or black) or lightening in certain parts of the growth.
D Is for Diameter
This is not to suggest that smaller growths don’t need to be looked at—includingskin tags(acrochordons)—but those larger than 1/4 inch will always be of particular concern.
E Is for Evolution
Typically, birthmarks do not change significantly. What evolution is referring to here is that the mole or growth is changing in size, appearance, and texture or causing new symptoms (such as itching, pain, or bleeding). This is cause for concern.
How to Tell the Difference Between Skin Cancer and a Mole
Example
The following photo is an example of melanoma that meets most of the ABCDE criteria. However, every case of skin cancer is unique, and a different individual’s malignancy could look quite different.
This photo contains content that some people may find graphic or disturbing.See PhotoLentigo maligna melanoma.DermNet / CC BY-NC-ND
This photo contains content that some people may find graphic or disturbing.See Photo
This photo contains content that some people may find graphic or disturbing.
If you notice any changes to your skin that worry you, see your healthcare provider or ask for a referral to a qualifieddermatologist. This is particularly true if any blemish or growth changes rapidly or bleeds easily.
Summary
Moles and marks on the skin should be regularly monitored when checking for skin cancer, but it’s not always easy to remember what to look for. The ABCDE rule is an easy way to remember different characteristics of the moles or skin marks that warrant a call to your healthcare provider for further examination.
Call your healthcare provider if you’re unsure about a mole or mark. It’s better to be overly cautious than to brush it off and have it end up being serious.
A Word From Verywell
Skin cancer can be stressful to think about, but it’s important to examine your skin for any changes, especially if you’re at increased risk for skin cancer or have many moles or marks that need monitoring. If it makes you nervous, talk with your healthcare provider about how you feel. Then, they might be able to have you come in more frequently just for quick checks.
3 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Ward WH, Lambreton F, Goel N, Yu JQ, Farma JM.Clinical presentation and staging of melanoma. In: Ward WH, Farma JM, eds.Cutaneous Melanoma: Etiology and Therapy. Codon Publications;2018:79-89. doi:10.15586/codon.cutaneousmelanoma.2017Apalla Z, Nashan D, Weller RB, Castellsagué X.Skin cancer: epidemiology, disease burden, pathophysiology, diagnosis, and therapeutic approaches.Dermatol Ther (Heidelb). 2017;7(Suppl 1):5–19. doi:10.1007/s13555-016-0165-yDaniel Jensen J, Elewski BE.The ABCDEF rule: combining the “ABDCEF rule” and the “ugly duckling sign” in an effort to improve patient self-screening examinations.J Clin Aesthet Dermatol. 2015;8(2):15.Additional ReadingDiepgen TL, Mahler V.The epidemiology of skin cancer.British Journal of Epidemiology.2002;146(s61):1-6. doi:10.1046/j.1365-2133.146.s61.2.x
3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Ward WH, Lambreton F, Goel N, Yu JQ, Farma JM.Clinical presentation and staging of melanoma. In: Ward WH, Farma JM, eds.Cutaneous Melanoma: Etiology and Therapy. Codon Publications;2018:79-89. doi:10.15586/codon.cutaneousmelanoma.2017Apalla Z, Nashan D, Weller RB, Castellsagué X.Skin cancer: epidemiology, disease burden, pathophysiology, diagnosis, and therapeutic approaches.Dermatol Ther (Heidelb). 2017;7(Suppl 1):5–19. doi:10.1007/s13555-016-0165-yDaniel Jensen J, Elewski BE.The ABCDEF rule: combining the “ABDCEF rule” and the “ugly duckling sign” in an effort to improve patient self-screening examinations.J Clin Aesthet Dermatol. 2015;8(2):15.Additional ReadingDiepgen TL, Mahler V.The epidemiology of skin cancer.British Journal of Epidemiology.2002;146(s61):1-6. doi:10.1046/j.1365-2133.146.s61.2.x
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Ward WH, Lambreton F, Goel N, Yu JQ, Farma JM.Clinical presentation and staging of melanoma. In: Ward WH, Farma JM, eds.Cutaneous Melanoma: Etiology and Therapy. Codon Publications;2018:79-89. doi:10.15586/codon.cutaneousmelanoma.2017Apalla Z, Nashan D, Weller RB, Castellsagué X.Skin cancer: epidemiology, disease burden, pathophysiology, diagnosis, and therapeutic approaches.Dermatol Ther (Heidelb). 2017;7(Suppl 1):5–19. doi:10.1007/s13555-016-0165-yDaniel Jensen J, Elewski BE.The ABCDEF rule: combining the “ABDCEF rule” and the “ugly duckling sign” in an effort to improve patient self-screening examinations.J Clin Aesthet Dermatol. 2015;8(2):15.
Ward WH, Lambreton F, Goel N, Yu JQ, Farma JM.Clinical presentation and staging of melanoma. In: Ward WH, Farma JM, eds.Cutaneous Melanoma: Etiology and Therapy. Codon Publications;2018:79-89. doi:10.15586/codon.cutaneousmelanoma.2017
Apalla Z, Nashan D, Weller RB, Castellsagué X.Skin cancer: epidemiology, disease burden, pathophysiology, diagnosis, and therapeutic approaches.Dermatol Ther (Heidelb). 2017;7(Suppl 1):5–19. doi:10.1007/s13555-016-0165-y
Daniel Jensen J, Elewski BE.The ABCDEF rule: combining the “ABDCEF rule” and the “ugly duckling sign” in an effort to improve patient self-screening examinations.J Clin Aesthet Dermatol. 2015;8(2):15.
Diepgen TL, Mahler V.The epidemiology of skin cancer.British Journal of Epidemiology.2002;146(s61):1-6. doi:10.1046/j.1365-2133.146.s61.2.x
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