Moles

Medically Reviewed on 4/20/2023

What are moles?

Picture of Dysplastic Nevus
Moles may be tan, brown, black, reddish-brown, red, purple, or skin-colored and perfectly flat or raised.

Besides being a small burrowing mammal and a unit of chemical weight, the term mole (about skin) describes a variety of skin imperfections. Many prefer the term beauty mark. The medical term for a mole is melanocytic nevus. Moles may be tan, brown, black, reddish brown, red, purple, or skin-colored and perfectly flat or raised. Most moles are smaller than a pencil eraser (about 1/2 inch).

Certain moles become darker and more apparent with sun exposure and pregnancy. Moles can occur anywhere on the skin, including the scalp, ears, eyelids, lips, palms, soles, genitals, and anal area.

A melanocytic nevus (plural nevi) is composed of masses of melanocytes, the pigment-producing cells of the skin. However, there are a variety of other skin lesions that are also mole-like. These include seborrheic keratoses, skin tags, dermatofibromas, lentigines, and freckles. In this article, the term moles will be synonymous with a melanocytic nevus.

What the causes and risk factors for developing moles?

The genes we inherit from our parents, along with our amount of sun exposure (especially during childhood) are major factors in determining mole numbers. Skin with more sun exposure tends to have more moles. However, moles may also occur in sun-protected areas.

Moles and freckles (medically termed ephelides) are darker than the surrounding skin. Moles may be raised or completely flat while freckles are always flat. Freckles and "sun spots" (medically termed lentigines) are due to an increase in the amount of dark pigment called melanin. Moles are more common in people prone to freckles. Freckles are flat spots that are tan, slightly reddish, or light brown and typically appear during the sunny months. They frequently appear on people with light complexions. Many people with blond or red hair and green or blue eyes are more prone to these types of skin spots. Sun avoidance and sun protection, including the regular use of sunscreen, may help to suppress the appearance of some types of moles and freckles.

Moles occur in all races (Caucasian, Asian, African, and Indian) and skin colors. Even animals have moles. Inadequately pigmented people who live in sunny climates and do not practice sun avoidance are likely to have more pigmented nevi. A mole is essentially nothing more than a mass of nested melanocytes at one spot in the skin.

Do babies get moles?

Yes. Moles may be present at birth or gradually appear later in the newborn period. Many children continue to develop moles through their teenage years and into young adulthood. Moles tend to grow very slightly in proportion to normal body growth. Congenital moles are those present at birth and so must have been present during fetal development. Other moles may arise later due to factors that are not genetic but environmental, such as sun exposure.

Can I still get new moles as an adult?

Yes. While many moles arise in the first years of life, the total number of moles typically peaks in the second or third decade of life to an average of 35. Most people do not develop new regular moles after the age of 30. Adults often develop non-mole growths like freckles, lentigines, "liver spots," and seborrheic keratoses in later adulthood.

New moles appearing after age 35 may require close observation, medical evaluation, and possible biopsy. A brand-new mole in an adult may be a sign of an evolving abnormal mole or early melanoma. It is important to have any new or changing mole evaluated by a dermatologist.

What else could it be?

Many other conditions mimic moles including freckles, lentigines, liver spots, seborrheic keratoses, melanomas, neurofibromas, hemangiomas, skin tags, café au lait macules, and pigmented basal cell cancers. The optimal way to distinguish between these other growths is by consultation with a dermatologist, which may include a skin biopsy. Sometimes, a mole may occur adjacent to or on top of a non-mole growth like a freckle or seborrheic keratosis. When in doubt, a skin biopsy can be very helpful in diagnosis.

What three basic types of moles are there? What are their symptoms?

Picture of Dysplastic Nevi (Atypical Moles)
Dysplastic nevi: Atypical moles whose appearance is different from that of a common ordinary mole.

There are three basic types or groups of moles:

  1. Regular and symmetrical
  2. Irregular
  3. Cancerous

Regular Moles

An atypical mole is another term for an irregular mole. Regular moles are typically benign and harmless. Regular moles are usually symmetrical, have regular borders, uniform color, and are about the size of a pencil eraser or smaller. Regular moles may be flat or raised. The presence of hair growing from a mole is unrelated to its cancer potential.

Irregular Moles

Irregular or atypical moles are usually asymmetrical, with irregular borders, and multiple colors, and tend to be bigger than the size of a pencil eraser. Irregular moles are often flat or nearly flat. Having more than 20-25 irregular moles may increase the person's overall risk of developing melanoma. The presence of a giant congenital mole greater than approximately 8-10 inches in size also may confer an increased risk of melanoma. Irregular moles signal the potential for developing melanomas over time. Irregular moles themselves rarely turn into melanoma or cancer.

Cancerous Moles

Cancerous moles called melanomas, are highly irregular and are often asymmetrical. Rarely, regular moles may evolve into melanoma over time. It is important to watch all moles closely for change or atypical features. In those with greater than 50 moles or several abnormal moles, monthly skin self-examinations and at least an annual full-body moles exam by a dermatologist are important in the early detection of abnormal moles and melanoma.

  • A -- Asymmetrical
  • B -- Irregular borders
  • C -- Multiple colors
  • D -- Diameter bigger than a pencil eraser
  • E -- Evolving, changing, or new

Irregular moles can occur anywhere on the body but are most commonly located on sun-exposed skin, especially on the upper back and shoulders where people frequently get their most severe sunburns. The risk of melanoma is greater on chronically sun-exposed skin like the shoulders, upper back, head, and neck. Ears are a particularly common site of atypical moles because of the difficulty in applying sunscreen and frequent sun exposure. Women have increased risks of atypical moles, particularly on the lower leg and calf. Any new or changing irregular mole on a woman's calf warrants immediate medical evaluation.

IMAGES

Moles See pictures of moles and other noncancerous and cancerous skin conditions See Images

Is there a blood test or X-ray to diagnose moles?

No, there are no blood tests or special X-rays for moles. There are, however, newer digital mole imaging technologies like the SIA scan (SIA = spectrophotometric intracutaneous analysis) or MelaFind that are now available to evaluate moles. These non-invasive, computerized mole-scan devices can help objectively examine a mole and capture information like size, amount, and pattern of pigment, blood flow, and other characteristics. Based on this information, changes in moles or irregular cells may be more readily identified. This technology is new and still developing.

What about UV cameras that show moles?

UV cameras using special black-and-white images depicting the amount of sun damage may be helpful in some situations to demonstrate sun damage. UV cameras do not diagnose moles or skin cancer.

What are treatment options for moles?

Surgical removal treats true moles. Fading or lightning creams, bleaches, freezing, or other chemicals do not treat moles. Fairly minor in-office procedures (involving the surgical excision of the entire lesion) can easily remove moles.

Regular moles do not necessarily need to be treated. A healthcare professional should surgically remove changing or medically suspicious moles in their entirety and send them to a lab for a special tissue examination called pathology.

Some people like their moles. Cosmetic improvement of the skin is a frequent request among people with moles. Some people may like their moles if they feel they confer uniqueness (like Cindy Crawford). Other moles produce potential negative social perceptions.

Although some countries and medical centers use lasers to remove some types of moles, laser treatments are not recommended for moles. Irregular moles need to be surgically removed and the tissue sent for testing. While sun spots or lentigines may respond to bleaching or fading creams, freezing with liquid nitrogen, laser, intense pulsed light, and chemical peels, true melanocytic nevi should not be treated by these methods.

Should my moles be removed using Mohs surgery?

No. Mohs surgery is not designed for mole removal but rather skin cancer removal. Standard or traditional surgery removes moles. The rapid freezing technique used for Mohs surgery tends to distort mole cells and may make the removed tissue more difficult to examine under the microscope.

Is there scarring from mole removal?

When the skin is cut, there will be some type of scarring produced by the healing process. Some people heal better than others. Some scars are more noticeable depending on their location and skin type.

There are many options for the treatment of surgical scars, including lasers, scar creams and gels, cortisone injections, and many other choices depending on the scar. Discuss ways to help minimize scarring with a doctor.

Can a plastic surgeon remove my mole?

Yes. Plastic surgeons may have additional and specialized training in cosmetic skin growth removal. Regardless of what type of doctor removes a mole, it is important to keep in mind that all mole removals will leave some type of scar.

Is there pain after mole removal surgery?

Most people report no or minimal discomfort after mole-removal surgery and require no pain medication. If there is pain, many people find that they prefer to take something for pain at the first hint of discomfort instead of waiting until the pain builds up to an unbearable level. If someone has mild or moderate pain, a doctor may advise taking acetaminophen (Tylenol) or another pain reliever over the counter. Aspirin or aspirin-containing pain relievers may cause increased bleeding. Rarely, prescription pain medications may be required for severe pain.

Can my mole grow back after removal?

Yes, there is a small chance that a mole can recur after mole surgery.

It is important to understand that no surgery has a 100% cure rate. A few mole cells may remain in the skin and may recur in the same or adjacent area. Some moles are more aggressive than others and need additional treatment and closer follow-up.

Good follow-up appointments with a physician are very important, especially in the first few years after irregular mole removal. Many people see their physician every six to 12 months after their diagnosis of atypical moles. Patients with more aggressive moles or moles in high-risk areas may need more regular follow-up appointments. A physician will recommend the proper follow-up for someone's specific condition.

Can people go out in the sun after mole removal surgery?

Yes. There are no specific sun restrictions after mole removal surgery. People may go out in the sun with sunscreen and protective hats and clothing. Overall, the sun is no one's friend, and people should avoid excess sun exposure. Excess sun exposure can cause melanoma. The use of sunscreen or other cover-ups on the scar is very helpful for at least six months after surgery to help minimize scarring. It is important to follow the physician's instructions for wound care and sun protection.

Do moles ever disappear spontaneously?

Yes. In some cases, moles may lighten or completely disappear later in life. In some instances, this is the result of the body's immune system attacking the mole and causing it to regress. One example of this is a "halo nevus." The presence of this phenomenon does not necessarily signal the presence of cancer. A doctor should evaluate the nevus on its own merits, exclusive of the presence of the halo.

When should I worry about a mole? What type of mole should not be removed?

New or enlarging moles may be worrisome, and a dermatologist should evaluate these promptly. While moles may increase in size, particularly before the age of 20, regular moles are unlikely to enlarge as people get older. A mole that has increased in size is not necessarily cancerous. Enlargement alone does not necessarily mean a mole is malignant. Some regular moles may increase in size and darken during pregnancy. Often, a simple mole biopsy by a doctor can help determine if a mole is irregular.

Regular moles pose essentially little to no health risk. It is not necessary to remove all moles. The vast majority of moles are not cancerous and generally do not become cancerous. However, it may be necessary for a pathologist to remove and examine any moles that are changing, growing, new, symptomatic, or bleeding. Periodic monitoring and medical evaluation of moles are important to help determine which moles need to be removed.

What does a cancerous mole look like?

Melanoma

This very dangerous form of skin cancer may appear even in young people and on parts of the body that are sun exposure as well as those that are protected. While the exact cause of melanoma is unknown, genetics and ultraviolet rays are known to play a part. Melanomas may arise from a previously normal mole or pigmented spot that has been present for many years. Melanomas may also arise from completely normal skin without an apparent preexisting mole. In comparison with benign (noncancerous) moles, melanomas tend to be larger, darker and have more irregular color and shape variations. Most melanomas are not raised, as many people tend to incorrectly assume.

Lentigo maligna ("malignant mole")

This is an uncommon fairly superficial skin cancer that generally occurs on the faces of older adults who have a history of considerable sun exposure. Over months to years, this condition may, if untreated, develop into a more aggressive malignant variety called lentigo maligna melanoma. There are hundreds of ordinary facial moles for everyone that is potentially malignant. A simple in-office test called a skin biopsy can help diagnose lentigo maligna.

Basal cell carcinoma

This is the most common type of skin cancer. These are usually pearly, pink, or reddish and may bleed easily. Pigmented basal cell carcinoma is a type of basal cell cancer that may be confused with melanoma, a benign mole, or a seborrheic keratosis because of its brown or dark color. A simple skin biopsy procedure can help diagnose this growth.

Does having more moles increase one's chance of getting melanoma?

Yes. The total number of irregular moles on one's body is one of the strongest indicators of the risk of developing malignant melanoma. There is also a direct relationship between the number of innocent moles on the skin and the chance of developing an abnormal or changing mole. The more moles a person has, the greater the risk of developing atypical moles and potentially melanoma.

When should I see a doctor?

Patients with unusual moles or pigmented spots should have a dermatologist evaluation. Even verbal descriptions and photographs cannot convey enough information for satisfactory self-diagnosis. Routine annual mole checks are an important part of general health screenings for those at risk for skin cancer. Birthdays are a good time to remember to schedule an annual "birthday suit" mole check. Since existing moles may change and new growth arise, periodic rechecks are necessary.

How often should I check my moles?

The American Academy of Dermatology recommends monthly skin self-exams and a full-body skin examination for adults as part of a routine annual health exam. It is important to have any new, changing, bleeding mole or growth examined by a dermatologist as soon as possible. If diagnosed and treated at an early stage, skin cancers (including melanomas) generally are curable.

Is it possible to prevent moles?

Since we cannot change our genetics, it is not possible to prevent all moles. The following prevention measures focus on sun avoidance and sun protection and include:

  • using sunscreens with SPF (sun protection factor) 50;
  • using wide-brimmed hats (6 inches);
  • using sun-protective clothing (shirts, long sleeves, long pants);
  • avoiding peak sun hours of 10 a.m. to 4 p.m.;
  • seeking shade and staying indoors.

Ideally, mole prevention is more effective than later trying to remove moles that have already developed. Mole removal will leave some type of scar at the site of the prior mole. Smaller moles are easier to remove and leave smaller scars. Larger mole removal often produces larger more unsightly scars.

When should I start sun protection?

Everyone, especially those predisposed to freckling, should start sun protection early in childhood. Much of the sun and UV skin damage occurs often while children under age 18. Fair-skinned people who are more prone to freckling and sunburns are also generally more at risk for developing moles and skin cancers. Sun sensitivity and easy burning may be warning signs of sensitive skin, which is highly vulnerable to sunburn and to potential skin cancer.

Subscribe to MedicineNet's Skin Care & Conditions Newsletter

By clicking "Submit," I agree to the MedicineNet Terms and Conditions and Privacy Policy. I also agree to receive emails from MedicineNet and I understand that I may opt out of MedicineNet subscriptions at any time.

Medically Reviewed on 4/20/2023
References
Damsky, W.E., and M. Bosenberg. "Melanocytic Nevi and Melanoma: Unraveling a Complex Relationship." Oncogene 36.42 Oct. 19, 2017: 5771-5792.

Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.

Piccolo, V., et al. "Dispelling Myths Concerning Pigmented Skin Lesions." JEADV 30 (2016): 919–925.

United States. National Cancer Institute. "Common Moles, Dysplastic Nevi, and Risk of Melanoma." Nov. 1, 2011. <http://www.cancer.gov/cancertopics/factsheet/Risk/moles>.
  翻译: