Moles or Skin Cancer: How to Tell the Difference

Have you ever come across a suspicious spot on your body and wondered whether it's moles or skin cancer? Take a look at the signs to watch for to determine whether your concerns about cancer and moles are valid. 

There are certain signs to look out for to tell the difference between a basic, everyday freckle and a cancerous mole. Your monthly self-exam is the first step in recognizing moles and skin cancer (you are doing a monthly exam, right?) and is a great way to keep an eye out for any problems. Self-exams are an excellent way of catching cancer early, when it often can be completely cured or more simply treated. 

First Steps for Spotting Concerns 

The first step to knowing the difference between cancerous and non-cancerous spots is to do a full-body exam. A dermatologist is your best resource for this step. A professional exam will be a clear foundation for identifying both healthy skin and warning signs of cancer. He or she can help you notice what is normal for your body, what to look out for and what can be cancerous. Once you have a baseline, you can watch out for changes in freckles or moles, which could be signs of skin cancer. 


Change is Not Good 

Changes in moles or new growth may be a sign of melanomas, such as basal cell carcinoma or squamous cell carcinoma. If a mole or growth seems to be growing or changing in any way, it could be cancerous. If a spot changes, itches, bleeds or is raw and doesn't heal, this may also be red flag. 

Know Your ABCDEs 

There are simple ways to spot troublesome moles or lesions, and this simple acronym can help you remember. Make sure you know your ABCDEs: Asymmetry, Border, Color, Diameter, Evolving. 

Asymmetry is an unevenness of the mole. If you draw a line through the middle of the spot, it should be symmetrical, or the same on both sides. If it's not the same on both sides, the mole is asymmetrical and may be cancerous. 

Borders of a normal mole or freckle are usually even. The borders of an early melanoma tend to be crooked or scalloped. Keep an eye out for strange edges in your spot because this may be a sign of cancer. 


Color is often another indicator of trouble. Moles that are different shades can be cancerous. Cancerous lesions can be multiple shades of tan, brown or black. It's also not abnormal to find melanomas that have red or blue coloring to them. 

The diameter of a melanoma is usually larger than a pencil eraser. Sometimes, when detected early, they can be smaller, but it's important to look out for large moles or lesions, which may be cancerous. 

An evolving mole may be a sign of cancer. A mole that changes size, shape, color, elevation or another characteristic, may be a cancerous mole. Additionally, other changes such as bleeding, itching or crusting are also signs of trouble. 


Find an Ugly Duckling 

Doctors have also come up with another simple way to remember the signs of a cancerous mole. The "Ugly Duckling" test is based on scientific research that shows that a person's moles tend to look like each other in the same way that siblings resemble each other. 

When you are doing your self-exam, look out for moles that do not look similar to the ones around them. A troublesome mole might be one that is darker or larger than the ones surrounding it, or it might be smaller or redder than its nearby counterparts. Spotting an "Ugly Duckling" may be a sign that the mole is cancerous, so if you find a spot that looks very different from the spots around it, have a doctor check it out. 

What Else Could it Be? 

There are plenty of types of moles or skin growths that are not cancerous. Most skin tumors aren't dangerous and do not turn into cancer. A typical mole, also known as a nevus, is a common type of skin tumor that isn't cancerous. A Spitz nevus is another type of mole that is often mistaken for a melanoma. Warts are also considered skin tumors, but they are not dangerous, either. Seborrheic keratosis is a black, tan or brown raised bump with a waxy texture that you don't need to worry about. Hemangiomas, commonly referred to as "strawberry spots" or "port wine stains" are also on the list of skin growths that aren't cancerous. 


The Two Types of Skin Cancer 

The types of moles that you should worry about are melanomas or non-melanomas. Skin cancer is the most common form of cancer. These two types of skin cancer vary in diagnosis and treatment, but it's important to know their signs and differences. 

Melanomas are the most dangerous form of skin cancer. They are rarer but are far more problematic. Melanomas cause malignant, or dangerous, tumors that can spread to different parts of the body. They begin in a part of the skin called the melanocyte, which creates melatonin. This is why they are often brown or black in color. Melanomas often appear on the back or chest in men and on the legs in women. 

It's important to note that people with darker skin have less risk of developing melanomas, but they still can get melanomas. Everyone should check for skin cancer, no matter their skin color or amount of sun exposure. 


Non-melanomas are the most common type of skin cancer. They include basal cell carcinomas and squamous cell carcinomas. There are other types of non-melanomas, but basal cell and squamous cell account for the largest amount of non-melanomas. 

Basal cell carcinomas comprise eight out of 10 cases of non-melanomas and usually show up in areas where there has been a lot of sun exposure. Squamous cell carcinoma accounts for about two in 10 cases of non-melanoma and appears on sun-exposed skin. It also can appear in scars or chronic skin sores. 

Be sure to check with a dermatologist if you find any troublesome spots. Remember, skin cancer often can be cured if detected and treated early. Now that you have a baseline, do some exploring and be on the lookout for the differences between moles and skin cancer.