Are Moles Cause for Concern?

Moles, also known as nevi, are small, tannish, pink, or skin-colored lesions. They are larger than freckles or skin tags. Moles often appear as a color other than the skin around them.

Some moles are present at birth. Others can appear through childhood and adolescence. They can form in response to changing hormone levels or exposure to ultraviolet (UV) light.

Moles are usually benign (noncancerous) and do not threaten your health. However, some moles can change and be a sign of melanoma skin cancer. This severe type of skin cancer spreads quickly, though it can be treated when found early.

This article explains what moles look like, how they differ, and their causes. It also explains the appearance of cancerous moles and how to protect yourself from skin cancer.

checking moles

Ivan-balvan / Getty Images

What Do Moles Look Like?

Moles are noncancerous skin growths. Generally, a benign mole has the following characteristics that do not change over time:

  • Round or oval shape
  • Uniform color in shades that can include pink, flesh-colored, tan, or brown
  • Raised or flat texture
  • Smooth borders separated from the surrounding normal skin

Common Types of Moles

The most common types of moles include the following:

Acquired Nevi (Common Moles)

Acquired nevi appear at some time during life. They most often form in childhood and early adulthood with the following characteristics:

  • Less than one-quarter inch (6 millimeters) in diameter, about the size of a pencil eraser
  • Often round or oval
  • Smooth surface
  • Slightly raised or dome-shaped
  • Distinct boundaries
  • Pink, tan, or brown, though darker in people with dark skin
  • Usually on areas above your waist
  • Little risk of developing into skin cancer

Dysplastic Nevi or Clark's Nevi (Atypical Moles)

About 10% of people in the United States have dysplastic nevi. These moles have the following characteristics:

  • Larger than one-quarter inch or the size of a pencil eraser
  • Irregular or poorly defined edges that may fade into the surrounding skin
  • Varying colors which range from tan to dark brown shades on a pink background
  • Usually flat
  • Typically on areas that are exposed to the sun though they may form elsewhere
  • Smooth, pebbly, or slightly scaly surface
  • Slight chance of changing into skin cancer, though rare

Congenital Nevi

Congenital nevi are typically present from birth. They are present in about 1 in 100 people and have the following characteristics:

  • Vary in size from less than one-quarter inch to covering your entire body
  • Wide range of variation in shape, size, color, hairiness, and surface texture in larger congenital nevi
  • Typically brown though colors range from reddish tan to black
  • Permanent "goosebump" appearance
  • Covered in hair ranging from a fine downy feel to thick long hair
  • Higher chance of developing into skin cancer than moles that form after birth, especially among larger nevi

What Causes Skin Moles?

Skin moles form when melanocytes (pigment-producing cells) in your epidermis (the top layer of skin) grow together in groups. They can be present at birth, but most moles appear in childhood and adolescence. New moles can also appear throughout your lifetime.

Moles that appear after birth typically form due to exposure to UV radiation from the sun or tanning beds. This UV exposure triggers melanocytes to produce melanin, a protective, skin-darkening pigment. UV light can also trigger these cells to cluster together and form moles.

Moles can also appear during adolescence and pregnancy in reaction to the changes in hormone levels typical during those times. Your risk of having moles increases with the following characteristics:

  • Genetics and family history of moles
  • Fairer skin, since this type of skin produces less protective pigment
  • Frequent exposure to sunlight or other sources of UV light
  • History of severe blistering sunburns
  • An abundance of moles

How Moles Are Treated

Most moles are not cancerous and do not require treatment. They pose no harm remaining in place without removal or other treatments.

Trying to self-treat or remove a mole is not advised. Doing so can alter the look and structure of the mole, making it harder for your healthcare provider to determine whether it is cancerous. Self-treatment of cancerous moles also raises your risk of scarring, infection, and spreading skin cancer cells if the mole is malignant.

Despite product claims, no prescription or over-the-counter drug is approved by the Food and Drug Administration (FDA) for treating moles. Contact your healthcare practitioner if you notice moles with the following characteristics:

  • Increase in size
  • Bleeding
  • Pain
  • Any physical change in appearance, color, or texture

Your healthcare provider can evaluate any suspicious moles and advise treatment as necessary. Moles that cause pain, physical embarrassment, or a risk of cancer are typically removed in an outpatient procedure that involves surgical removal, burning, or shaving.

After removal, all moles are sent to a laboratory for evaluation. If there is evidence of skin cancer, your healthcare provider will establish a treatment program to meet your needs.

Which Moles Could Lead to Cancer?

Most moles are normal and won't lead to cancer. However, a mole can progress to skin cancer as a result of the damage that UV rays cause to melanocytes.

Moles are not supposed to change in size, shape, or texture. Contact your healthcare provider if your mole has any of the following "ABCDEs" of skin cancer:

  • Asymmetry: Two halves of the mole that don't match if you draw a line down the center
  • Border: Uneven or irregular borders, possibly with notched or ragged edges
  • Color: Loss of color or a change to multiple shades of brown or black that's sometimes mixed with gray, white, blue, or red
  • Diameter: Larger than one-quarter inch
  • Evolution: Evidence of evolution (change) in the appearance of a mole

While most normal moles on the same person resemble one another, melanoma stands out as an "ugly duckling" compared to the other moles.

Diagnosing Cancerous Moles

Diagnosing cancerous moles usually begins with a comprehensive physical examination that includes the following:

  • Questions about mole symptoms, such as pain, itching, and/or bleeding
  • Review of risk factors for skin cancer such as sunburn history and family history of skin cancer
  • Visual examination of the mole with attention to the size, shape, color, texture, and other characteristics of the mole

If your provider determines the mole may be cancerous, they will perform a skin biopsy to confirm the diagnosis. This involves removing a section of the suspicious area and sending it to a lab for evaluation under a microscope.

The most common techniques used to perform a skin biopsy include the following:

  • Shave biopsy: With this technique, the top layers of the mole are shaved off with a small surgical blade. A shave biopsy is used for superficial moles primarily located on the epidermis without extending to the deeper layers of your skin.
  • Punch biopsy: This involves the use of a tool that looks like a tiny round cylinder to remove a deeper sample than shaving. The tool is rotated on the skin until it cuts through all the skin layers. The edges of the biopsy site are often stitched together.
  • Excisional biopsy: This type of biopsy involves the use of a scalpel (surgical knife) to surgically remove the entire mole along with a small margin of normal skin around it. It is typically done for moles in which there is a high suspicion of skin cancer.
  • Incisional biopsy: This technique involves the removal of a portion of the mole using a scalpel. A wedge or sliver of skin is removed.
  • Reflectance confocal microscopy (RCM): This relatively new type biopsy, known as an optical biopsy, is performed without the need to remove samples of skin. Though widely used in Europe, it has limited availability in the United States.

How Are Moles Removed?

A dermatologist typically removes moles. Before removal, the mole may be treated with an anesthetic to numb it to reduce pain. In most cases, mole removal is a short outpatient procedure that involves one of the following techniques:

  • Surgical excision: This involves cutting out the entire mole with a scalpel. Stitches are used to close your skin. Surgical excision is typically used for moles that go underneath your skin or those in which skin cancer is a reasonable concern. When large nevi are removed, a skin graft may be needed to cover the treated area.
  • Surgical shave: This procedure involves the use of a surgical blade to remove the mole. Layers of the mole are shaved off until it is gone. Stitches usually are not needed.
  • Laser mole removal: This technique delivers small bursts of light radiation to destroy the mole tissue. It is often used for small, flat, benign moles in hard-to-reach locations or those on sensitive areas like your face.

Protecting Yourself From Skin Cancer

Protecting yourself from skin cancer requires consistently taking the following precautions to protect your skin from UV radiation:

  • Stay in the shade, especially between 10 a.m. and 4 p.m. when UV rays tend to be the strongest.
  • Wear protective clothing, a hat, and sunglasses with UV protection to provide extra protection from the sun.
  • Avoid getting sunburns, which can increase your risk of skin cancer even years later.
  • Use a broad-spectrum (UVA/UVB) sunscreen with a sun protection factor (SPF) of 15 or higher daily. Use a water-resistant, broad-spectrum sunscreen with an SPF of 30 or higher when you plan to be outside for extended periods.
  • Thirty minutes before going outside, apply 1 ounce (2 tablespoons) of sunscreen to your entire body. Reapply every two hours or after excessive sweating or swimming.
  • Examine your skin from head to toe, back and front, including your scalp, monthly.
  • Visit a dermatologist annually for a professional skin exam to identify signs of skin cancer early.
  • Do not use indoor tanning beds.

How to Self-Examine and Monitor Moles

You can self-examine yourself and monitor moles to identify signs of melanoma as early as possible. To get the best results, stand without clothes in front of a full-length mirror in a well-lit room.

The first time you do a self-exam, record the patterns of moles, freckles, and blemishes so you can compare and track changes in later months. Look at pictures of melanoma so you know how a suspicious mole appears. Your healthcare provider should examine any new moles or changes in existing ones.

Follow these instructions to perform a head-to-toe examination monthly unless your healthcare provider advises them more often due to your skin cancer risk:

  • Check your face, especially your lips, nose, mouth, and the front and back of your ears.
  • Use a comb or blow-dryer to move hair away from the scalp to make it easier to examine. Go over the entire surface of your scalp and expose each section for observation.
  • Facing the full-length mirror, examine your torso, including your neck, chest, and abdomen. Lift your arms and check the sides of your upper body.
  • Facing away from the full-length mirror, hold a handheld mirror to examine your back torso. Examine your back, shoulders, the back of your neck, your buttocks, the backs of your thighs, and any other area on the back of your body.
  • Sitting on a chair, use the handheld mirror to examine the back of each leg, your genitals, the insides of your thighs, and the tops and soles of your feet. Check your toenails and between your toes.

Summary

A mole, also known as a nevus, consists of certain types of pigment cells that grow in clusters. They are common growths that are often benign and harmless.

Most adults have between 10 and 40 moles. They can be present at birth or appear later in life. When moles occur later, it is often in response to UV light exposure or changes in hormones.

Moles that change in shape, size, or texture can be a sign of melanoma, a serious form of skin cancer. Knowing what to look for can help you find signs of these changes before they become a severe problem. When found early, melanoma has a better chance of being cured.

19 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Anna Zernone Giorgi

By Anna Giorgi
Anna Zernone Giorgi is a writer who specializes in health and lifestyle topics. Her experience includes over 25 years of writing on health and wellness-related subjects for consumers and medical professionals, in addition to holding positions in healthcare communications.