Fact Checked

How do I Identify a Cancerous Mole?

Marjorie McAtee
Marjorie McAtee

A cancerous mole typically has certain physical characteristics that make it distinguishable from a non-cancerous, or benign, mole. The initialism ABCD can help you remember the characteristics of a cancerous mole. "A" stands for asymmetrical, because cancerous moles generally aren't the same shape, size or thickness on both sides; "B" stands for borders, because cancerous moles usually have jagged, badly delineated borders. "C" stands for color, because these moles are usually irregularly colored, mottled or dappled; "D" stands for diameter, because cancerous moles are usually larger than 6 mm (0.24 inches) in size.

Just because a mole fits some or all of these visual criteria, it doesn't necessarily mean it's a cancerous mole. Usually only a dermatologist can make that distinction. A doctor may choose to remove the mole immediately in either case.

A raised mole.
A raised mole.

Not all moles or skin tumors are cancerous. Most are probably benign. Skin moles known as dysplastic nevi may possess some of the characteristics of a cancerous mole, and other skin growths may also develop suspicious characteristics. Sometimes, these moles can become cancerous later on. People who have them may be considered to have a higher risk for skin cancer, particularly malignant melanoma.

Woman with a mole above her upper lip.
Woman with a mole above her upper lip.

Benign moles are usually fairly uniform in appearance. They are generally symmetrical in shape, with clearly defined, smooth edges. They are often the same color as the skin, and if they are a different color, then that color will show little variation across the surface of the mole. Benign moles are typically no more than 6 mm (0.24) in diameter. Size alone does not always indicate a cancerous mole, but, if a mole shows other characteristics of malignancy, and is larger than 6 mm (0.24 inches) in size, it could be a cause for concern.

Moles that are large, uneven in shape, or jagged around the edges could be cancerous. Moles that are not uniform in color could be cancerous. Moles that change in shape, color, or size could be cancerous.

Doctors typically prefer to remove moles with any characteristics of being cancerous.
Doctors typically prefer to remove moles with any characteristics of being cancerous.

It is considered important to have all moles, skin growths, and tumors evaluated by a dermatologist. Many moles with characteristics of malignancy are not, in fact, cancerous. Many dermatologists practice immediate removal of all moles with cancerous characteristics, as a preventative measure. Some forms of skin cancer, such as melanoma, can spread quickly and metastasize to other parts of the body. Most dermatologists advocate monitoring the appearance of all moles and seeking medical attention if a cancerous mole is suspected.

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Discussion Comments


I have a mole just underneath my armpit near my back on my breast. I hadn't noticed it before because it's not an area that I always check, but it seems an OK size and everything. The only thing is, when I discovered it, I realized that the color of the mole was sort of bleeding outwards so that it went from the dark mole to a light brown to my fair skin color. I think I might get it checked out.


I got my mole cut off about two or three months ago and my dad did it and it has a red circle around it. I didn't like it being there, so I had him cut it off and I'm worried I might have cancer, but my mom says I'm fine. Is this a sign of cancer?


I had a very small, even, round, black mole on the side of my heel for who knows how long. My dermatologist wanted to do a biopsy which I thought was ridiculous as it did not fit any of the characteristics of cancerous moles. A week later I got the call that it was melanoma stage 0. I was shocked. I have olive skin and don't bask in the sun. I use sunscreen and I'm 41.

Two weeks later the cancer center removed it, plus good tissue to make sure they got it all and put on a skin graft from my bikini line to fill in the skin they took. I was off my feet for 10 days to heal. I still can't tell what is a normal mole and what is not, because it really looked normal.


My Mom has a fairly large mole right beside her nose and I really have not thought too much of it, until reading this article of course.

In the anagram ABCD used to check out moles, the D for diameter is what has me worried. If I had to guess the diameter of a her mole, I would say around one inch, which is a whole 3/4 of an inch bigger than a non-suspicious looking mole.

I think I have just recently took notice to her mole, since I do not see her on a regular basis, like I did when I was a child. Now I notice a lot more things about my family than I used to, as I only see most of them a few times a year. It seems like the more you see someone, the less you notice about them, and the less you see someone, the more you notice about them.

I am going to call my Mom tomorrow and ask her to please go to a dermatologist and have her mole removed as soon as possible. I need this weight of worry lifted off of my shoulders immediately.


I am glad I took Anatomy and Physiology my Junior year of high school, because I learned about benign and cancerous moles in this class. One of the only classes I have retained what I have learned from ten years ago.

My Anatomy and Physiology teacher really hit home the concept of us having our skin checked regularly for skin cancer. She told how her sister struggled with melanoma cancer so bad, her and her family thought she would not survive it. Luckily she did though!

Our teach drilled in all of our brains the importance of knowing and using the ABCD anagram for checking any moles we may have. I remember that year I was obsessed with checking to make sure my moles were not suspicious or changing in any way.

I really should continue to check on my moles, especially anytime I am outside for more than a few minutes.

Even in the winter we can still get skin cancer, as the sun is always out each day, whether we feel its warmth or not. Therefore, we should all wear sunblock and check ourselves and our moles frequently.


This article makes me wonder if I should go to the dermatologist and get my moles removed, although they don't seem have any of the suspicious characteristics of cancerous moles, as outlined in the ABCD anagram.

The only thing that may be a bit suspicious about my three moles, is that they are not anywhere near the same color as my skin is. I am fair skinned, and my moles are dark brown. They seem to be solidly dark brown though, they don't vary in color.

Maybe I should just get my moles removed anyway, so at least I won't have to worry about them anymore.

I wonder if even if a mole does not have any alarming characteristics, it may still have a slight chance of being cancerous anyway? Does anyone know if this may have some truth behind it?


You know, I know a lot of people who don't know anything about identifying cancerous moles. Which is crazy because I remember looking at pictures of skin cancer moles when I took health in college. My teacher was really adamant that we all learn the signs of skin cancer.

I personally think everyone should learn this information in school. It's life saving!


@JaneAir - Yes it is a good idea to go see a doctor to get a check up. Awhile ago, I was looking at cancer moles pictures online and I totally panicked. I went and had three moles removed that all turned out to be benign. However, I'm glad I got them removed because now they can't develop into skin cancer.

Anyway, I have a funny story about identifying cancer moles. I had a friend in college who worked at sports bar where the waitresses were dressed in very skimpy clothing. One day, she waited on a table of doctors. After they paid their bill, one of the doctors took her aside and told her that she needed to get a mole she had on her leg checked out.

She went to the doctor and she ended up having skin cancer! She's fine now, but I'm not sure what would have happened if she hadn't ended up with that table!


I read somewhere that people are more likely to develop skin cancer in a pre-existing mole. So, if you get skin cancer you might not develop new moles. Instead, the moles you already have might start changing in appearance.

That's why it's really important to monitor all of your moles for skin cancer symptoms. I personally think it's a good idea to just go see a dermatologist for skin cancer screening once a year. It's really hard for a non-medical person to tell if they have skin cancer. Just look at all the comments on here about people who freaked out over a mole that turned out to be nothing!


I have had a mole since I was two years old that has grown with me. I think that it is finally through growing, but it's the biggest one I have. It sticks up from my skin nearly half an inch.

It isn't discolored or jagged, so I haven't been too concerned about it. I do wonder if the size makes it dangerous, though.

I get a checkup every year, and I get my blood and urine checked for just about everything. My doctor has never told me that I have any signs of cancer. However, she hasn't seen the mole.

Should I be worried about one that has been with me for so long? I feel pretty safe assuming that it is benign, because I've had it for thirty-one years.


@kylee07drg - Your skin sounds about like mine. I can spend hours outdoors with sunscreen on and only get a light tan, but I usually have to go through a burn to get it. I freckle easily, and moles seem to pop up along with the spots.

I keep an eye out for cancerous mole symptoms. Last year, I saw a mole on my back that was shaped like a kidney. It had jagged edges, and it also had a sort of blue hue to part of it.

It scared me, because it exhibited so many signs of being cancerous. I had it totally removed, and I found out that it was a dangerous mole. The doctor got all of it off my body, so I'm safe now.


Since I have pale skin that burns easily in the sun, I have to watch for skin cancer moles. It seems that the more time I spend in the sun, the more moles I develop, though they are usually normal looking.

My dad is in his seventies, and he has had a couple of precancerous moles removed from his skin. One was on his scalp in a spot where the hair is thin, and the other was on his arm.

He once was pale like me, but years of working in the sun have made him darker. Moles just seem to appear out of nowhere on him now, so he has to have regular appointments with a dermatologist.

I got a swimming pool a few years ago, and ever since then, I have spent a lot of time in the summer sun. I have seen at least one new mole each year develop, so I always check my skin carefully for abnormal ones. I pay special attention to my back, where they tend to grow the most.


I had a nearly flat mole right in front of my ear that seemed suspicious. It had a super rough texture, and it was growing at a noticeable rate.

I went to my doctor, and she set me up an appointment with a plastic surgeon to have it removed. He deadened the area, and even though I couldn't feel anything, I could hear his knife slicing into my skin.

It helped that he made small talk with me as he did it. I found it kind of funny that we were talking about the weather as he cut off part of my face!

The mole turned out to be benign. I had a red scar on my face for a long time, but today, I can't even tell I had anything done.


I have a friend who was going to medical school and she became very concerned about a mole on her leg.

In her years of schooling, she had seen many cancerous mole pictures. She knew what to look for and what features could likely be cancer.

This was really bothering her and she thought for sure this was cancerous and wondered how it might affect her medical training.

It was a great relief when the results came back normal after she had the mole removed. This showed me how important it is to make sure and get biopsy results.

Even though it may look like it is normal, or may look like it could be cancerous, you just never know until you have it checked out.


I was born with a mole on the back of my shoulder, and never had much of a problem with it when I was younger. Once in a while if it got rubbed the wrong way, it would bleed a little bit.

I tried to compare it to pictures of cancerous moles to determine if it looked like cancer, or if there were any significant changes to the size and color of the mole.

This is hard to do when it is in an area that you can't see too well. I finally decided I didn't want to worry about it anymore and just have it removed.

This really was an easy procedure, and the results came back negative. I just feel better about having it gone and not have the nagging worry if it might become a cancerous mole.


My husband was being seen because of an upper respiratory condition and the doctor noticed a suspicious mole on his chest.

She didn't like the look of it as it had the possible signs of a skin cancer mole. He made an appointment with a dermatologist to have it checked out, and it was a basal cell carcinoma.

They removed this mole and he had to go back every 6 months for checkups for a couple of years. This is usually an easy type of skin cancer to treat, but it can still be a little bit unsettling.

I don't know how long he might have gone if he had not been to the doctor because of his persistent cough. Thankfully he was seen right away and got it treated before it got worse or spread to another part of his body.


I had a suspicious mole removed when I was a teenager. I had had it my whole life and I actually kind of regret having it removed, because it was kind of distinctive (on one shoulder blade, so visible in a tank top or a sleeveless formal) and hardly suspicious at all.

But the dermatologist said that the only way to tell if it was cancerous or not was to remove it. It's sort of treatment and biopsy all in one. Once it's removed, they can test it to see if it's cancerous. Most often it isn't, or it's just a basal or squamous cell carcinoma. (These don't metastasize and can be disfiguring if left unchecked, but rarely dangerous.) If it's melanoma, I think they do more testing to make sure it hasn't spread.

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    • A raised mole.
      By: paulandlara
      A raised mole.
    • Woman with a mole above her upper lip.
      By: donatellina
      Woman with a mole above her upper lip.
    • Doctors typically prefer to remove moles with any characteristics of being cancerous.
      By: Milissenta
      Doctors typically prefer to remove moles with any characteristics of being cancerous.
    • Skin cancer can only be truly diagnosed through lab tests on suspect moles.
      By: Alexander Raths
      Skin cancer can only be truly diagnosed through lab tests on suspect moles.
    • Moles may be malignant if they are asymmetrical, have irregular borders, appear to spread their color into surrounding skin or change in appearance.
      By: bertys30
      Moles may be malignant if they are asymmetrical, have irregular borders, appear to spread their color into surrounding skin or change in appearance.