What Is a Mole?
A mole, also called a nevus, is a common skin growth made of pigment-producing cells called melanocytes. Moles may be flat or raised, round or oval, tan, brown, black, pink, or skin-colored. They can appear anywhere on the skin, including the face, scalp, trunk, arms, legs, palms, soles, and under the nails.
Acquired Moles
Acquired moles develop after birth, often during childhood, adolescence, or young adulthood. Having new moles in childhood and early adulthood can be normal. A new or changing mole later in adulthood should be checked. Most moles are benign, meaning they are not cancer. However, because melanoma can sometimes look like a mole—or arise near or within one—changing or unusual moles should be evaluated by a dermatologist. The National Cancer Institute notes that common moles are not cancerous, but people with many moles or atypical moles may have a higher melanoma risk. (Cancer.gov)
Types of Moles
Common Moles
Common moles are usually small, evenly colored, and symmetrical. They often appear during childhood or adolescence and may darken with sun exposure, hormones, or pregnancy.
Congenital Moles
Congenital moles are present at birth or appear shortly afterward. Small congenital moles are usually harmless, but larger congenital melanocytic nevi require closer monitoring because melanoma risk is higher in large or giant lesions. (DermNet®)
Acquired Moles
Acquired moles develop after birth, often during childhood, adolescence, or young adulthood. Having new moles in childhood and early adulthood can be normal. A new or changing mole later in adulthood should be checked.
Atypical Moles / Dysplastic Nevi
Atypical moles, also called dysplastic nevi, may be larger, irregularly shaped, or uneven in color. They are not melanoma, but they can resemble melanoma and may signal a higher overall melanoma risk, especially when a person has many of them. (Cancer.gov)
Dysplastic Nevus Syndrome
Some people have many atypical moles and a family history of melanoma. This pattern may be called dysplastic nevus syndrome or familial atypical mole syndrome. These patients usually need regular full-body skin exams and careful mole monitoring.
Moles vs. Skin Cancer: The ABCDE Warning Signs
Dermatologists often use the ABCDE rule to help identify moles that should be examined:
A: Asymmetry
One half does not match the other.
B: Border
The edges are irregular, blurred, notched, or scalloped.
C: Color
The mole has multiple colors, such as tan, brown, black, red, white, blue, or gray.
D: Diameter
The mole is larger than 6 mm, about the size of a pencil eraser. Smaller melanomas can also occur.
E: Evolving
The mole is changing in size, shape, color, elevation, symptoms, or behavior.
The “E” is especially important. A mole that is changing, bleeding, itching, painful, crusting, or noticeably different from your other moles should be evaluated.
The “Ugly Duckling” Sign
Another helpful warning sign is the ugly duckling mole. This is a mole that looks different from your other moles. Even if it does not meet every ABCDE criterion, a mole that stands out should be checked.
What Causes Moles?
Moles form when melanocytes grow in clusters. Factors that influence mole development include:
Genetics
Some people inherit a tendency to develop many moles or atypical moles.
Sun Exposure
UV radiation from the sun and tanning beds can contribute to mole development and increase skin cancer risk.
Skin Type
People with fair skin, freckles, a history of sunburns, or many moles may have a higher melanoma risk. However, melanoma can occur in all skin types.
Hormonal Changes
Moles may darken or change slightly during puberty, pregnancy, or other hormonal shifts. Even so, significant or suspicious changes should still be examined.
Moles in Skin of Color
People with darker skin can and do get moles and melanoma. Melanoma is less common in darker skin types, but it may be diagnosed later, sometimes in areas that are not heavily sun-exposed, such as the palms, soles, nails, or mucous membranes. Any changing spot, dark streak in a nail, non-healing sore, or unusual growth should be evaluated.
When Should You See a Dermatologist for a Mole?
Schedule a dermatology visit if you notice:
- A mole that is changing
- A new mole after age 30
- A mole that bleeds, crusts, hurts, or itches
- A mole with irregular borders or multiple colors
- A mole that looks different from your others
- A dark streak under a nail
- A personal or family history of melanoma
- Many moles or atypical moles
Do All Moles Need to Be Removed?
No. Most moles do not need removal. A dermatologist may recommend removal if a mole is suspicious, irritated, frequently traumatized, cosmetically bothersome, or difficult to monitor.
When a mole is removed because of concern for skin cancer, the tissue is usually sent to a laboratory for pathology testing. This is one reason suspicious moles should not be burned off, lasered, or removed at home.
Mole Removal
Moles may be removed for medical or cosmetic reasons. The best method depends on the mole’s appearance, location, depth, and whether a biopsy is needed. Because removal technique, scarring, pathology, and aftercare deserve a full discussion, see our related page: Mole and Growth Removal
Skin Cancer Screening for Moles
A full-body skin exam allows a dermatologist to evaluate moles and other skin growths using clinical expertise and, when appropriate, dermoscopy. Patients with many moles, atypical moles, a history of melanoma, or a strong family history may need regular skin checks.
Frequently Asked Questions
Yes. Moles are common, and most are harmless.
Rarely, a mole can become melanoma, but many melanomas arise as new spots rather than from existing moles. Any changing or unusual mole should be checked. (Cancer.gov)
New moles are common in children and young adults. A new mole after age 30 deserves closer attention, especially if it looks different or changes.
No. Atypical moles are not melanoma, but they can look like melanoma and may be associated with increased melanoma risk.
Sometimes. Cosmetic mole removal may be reasonable if the mole is benign and bothersome. A dermatologist should evaluate it first.
No. At-home mole removal can cause infection, scarring, incomplete removal, and missed diagnosis of skin cancer.
Yes. Melanoma can occur in all skin types, including Black, Hispanic, Asian, Middle Eastern, and other skin of color patients.