While for many of us moles are just brown spots on our body we pay little mind, moles come in many shapes, sizes and forms that can tell us important things about our skin health. Understanding all of the varieties of moles out there and how to identify them is the best way to prevent skin cancer and stay healthy.
In addition to the information on this page, you should use the SkinVision app to check your skin for skin cancer and get an instant risk indication.
First of all, what is a mole?
A mole or nevus is a dark, raised spot on our skin comprised of skin cells that have grown in a group rather than individually. These cells are called melanocytes and are responsible for producing melanin, the pigment (color) in our skin.
Moles can form from sun exposure, but we are also born with them, inheriting them genetically. Although number of moles varies from person to person, fair skinned people generally have more moles due to lower amounts of melanin in their skin, and the average adult has between 10 and 40 moles. Moles can even come and go with hormonal changes such as pregnancy or puberty.
Most people develop more moles on their skin naturally with age and sun exposure, and — most of the time — these moles are harmless. However, we need to conduct skin checks regularly (recommended monthly, especially if you have a relative with skin cancer, or at least every three months) to see if our moles have changed.
Types of skin moles:
Not all moles are created equal. Here’s a quick guide to mole types and what they mean for our skin. It’s good to note that moles are categorized by multiple factors, including when they developed, where they are located in the skin and if they exhibit typical or atypical symptoms. That means moles are often described by multiple classifications. For instance, you can have a common acquired junctional nevus or an atypical congenital nevus.
A common mole is one that is usually about 5-6 mm in diameter, has distinct edges, a smooth, dome-like surface and even pigmentation. These moles are usually found on skin regularly exposed to the sun and have the potential to turn into skin cancer, but it is a rare occurrence.
Atypical moles, or dysplastic nevi, are moles that exhibit irregular symptoms. They usually have fuzzy or blurry borders, are varied in color, larger than most moles and have both flat and raised components. While dysplastic nevi share a lot of the same signs of pre-cancerous or cancerous moles, most dysplastic nevi are benign. However, a person with many dysplastic nevi is at an increased risk for skin cancer. The more dysplastic nevi a person has, the higher the risk. Regular self-examinations are important to detect changes in these types of moles.
Mole types by time
Congenital moles, also known as congenital nevi, are moles that are present at birth. They are caused by melanocyte cells in the dermis (middle layer of skin), epidermis (outer layer of skin), or both. These types of moles can range in size and are sometimes referred to as birthmarks. Congenital nevi can be at risk of developing into melanoma later in life and should be monitored as you enter adolescence and adulthood.
Acquired moles are moles that appear during childhood and adulthood. Most of these moles are benign and pose no risk, although sometimes they can turn into cancerous moles with age. This is the most common type of mole, and it is usually caused by repeated sun exposure.
Mole types by location
Junctional Melanocytic Nevi
Junctional melanocytic nevi are moles that occur from an accumulation of melanocytes where the dermis and epidermis meet. These moles are typically slightly raised with regular borders and dark pigmentation, although they can range in color from tan to dark brown. People normally acquire these moles in childhood to early adulthood, because, as we age, it is common for melanocytes to migrate down to deeper layers of the skin.
Intradermal nevi are flesh colored moles that often blend in with your surrounding skin. Their pigmentation is not as dark as junctional melanocytic nevi because they are located in the dermis, or the middle layer of your skin. These moles usually develop in late childhood or throughout adulthood and are very common and usually benign.
Compound nevi show signs of both intradermal and junctional nevi, with melanocyte cells located in the dermis and dermo-epidermis junction. These moles usually have a central raised area with flat areas around the edges. They usually have distinct borders and even pigmentation.
Other mole types to note
Halo nevi are raised moles that have a ring of skin around them that has lost pigmentation due to inflammatory infiltrating cells. Doctors are still trying to understand why this reaction occurs, but if diagnosed properly, these moles are benign and require no treatment unless for cosmetic reasons.
How to know if your mole is safe
Moles that are considered “safe”, or not at risk for cancer, generally have a few common features.
They usually resemble common moles and have:
· neat edges,
· a smooth or dome-like shape,
· are around ¼ inch (6 mm) in diameter,
· and stay the same shape, size or color over time.
It’s important to take a quick inventory of the moles on your body so that you can recognize any changes that may occur over time. Understanding what’s normal for your body is key for catching early skin cancer symptoms and prevention.
Warning signs that it may be cancerous
Look for these indicators that your mole may be cancerous:
· A change in size (getting larger)
· A change in shape (especially with irregular edges)
· A change in color (especially getting darker or exhibiting multiple shades)
· A loss of symmetry (common moles will be perfectly round or oval and are usually symmetrical)
· Itchiness, pain or bleeding (maybe even forming a scab)
· Exhibiting three different shades of brown or black
· A change in elevation (thickening or raising of a flat mole)
If you notice any of these symptoms, contact a doctor to have your mole examined.
ABCDEs of Moles
It can be difficult to remember all of the things to look out for during a skin check. That’s why doctors advise using the ABCDE method to make things simpler.
Check your skin for these signs during self-examinations:
· Asymmetrical – the mole is distinctly asymmetrical
· Border – the mole has uneven borders
· Colors – the mole contains at least two distinct colors
· Diameter – the mole is bigger than ¼ inch or 6 mm across
· Enlargement – the mole grows in size over time
Check your mole
The best way to decipher if a mole — of any type — is safe or at risk is to check them frequently. Any changes are usually a sign that the mole should be checked out by a doctor. Use the SkinVision app to scan your moles for signs of risk and to connect you with a dermatologist nearby. Download it for free.