Dysplastic Nevus (Atypical Mole)
An unusual-looking mole, also called an atypical mole
Quick Facts
- Type: Skin growth (atypical mole)
- Appearance: Irregular shape, border, or color
- Significance: Marker of higher melanoma risk
- Usual approach: Monitoring; removal if changing
Overview
A dysplastic nevus, also called an atypical mole, is a mole that looks different from an ordinary mole. It may be larger, have an irregular or fuzzy border, or contain a mix of colors. Under the microscope, the cells also have an unusual but not cancerous appearance. Most people with dysplastic nevi have only one or a few, while some have many.
The large majority of dysplastic nevi are harmless and stay that way. However, having atypical moles, especially many of them, is a marker that a person has a somewhat higher chance of developing melanoma, a serious type of skin cancer. A dysplastic nevus itself is not cancer, but because it can occasionally change, knowing how to monitor moles and recognize warning signs is important.
Symptoms
A dysplastic nevus is usually painless and noticed by its appearance. Typical features include:
- Larger than a common mole, often bigger than a pencil eraser
- An irregular, notched, or blurred border
- A mix of colors, such as tan, brown, pink, or black
- A flat part and sometimes a slightly raised center
These moles can appear anywhere, including areas not usually exposed to the sun. Most do not change, but any mole that begins to grow, change color, itch, or bleed should be checked.
Causes
Moles, including atypical ones, form from clusters of pigment-producing cells in the skin. Several factors influence their development:
- Genetics: A tendency to develop many or atypical moles often runs in families.
- Sun exposure: Ultraviolet light contributes to mole formation and to overall melanoma risk.
- Skin type: Fair skin that burns easily is associated with more moles and higher risk.
Why a particular mole becomes atypical is not fully understood, but it reflects a combination of inherited and environmental factors.
Risk Factors
- A large number of moles overall
- A family history of atypical moles or melanoma
- Fair skin, light hair and eyes, and a tendency to sunburn
- A history of frequent or intense sun exposure or sunburns
- A personal history of melanoma
Diagnosis
Dysplastic nevi are evaluated by examining the skin and, when needed, sampling a mole:
- Skin examination: A doctor or dermatologist inspects moles, sometimes using a magnifying tool called a dermatoscope.
- Biopsy: If a mole looks suspicious or is changing, it may be removed and examined under a microscope to check for atypical or cancerous cells.
- Photographic monitoring: Tracking moles over time with photos to detect changes, especially in people with many atypical moles.
Treatment
Most dysplastic nevi do not need to be removed, and treatment focuses on monitoring and prevention:
- Regular monitoring: Routine skin checks by a clinician and self-examination at home.
- Removal of suspicious moles: A changing or worrisome mole is removed and examined; this is a simple office procedure.
- Sun protection: Reducing ultraviolet exposure to lower overall skin cancer risk.
People with many atypical moles or a family history of melanoma may be advised to have more frequent skin checks.
Self-Care and Prevention
- Use the ABCDE rule to watch for warning signs: Asymmetry, Border irregularity, Color variation, Diameter larger than a pencil eraser, and Evolving (changing) moles
- Examine your skin regularly and note any new or changing moles
- Protect your skin from the sun with sunscreen, clothing, and shade
- Avoid tanning beds
- See a dermatologist for routine skin checks if you are at higher risk
When to See a Doctor
See a doctor or dermatologist if a mole changes in size, shape, or color, develops an irregular border, itches, bleeds, or does not heal, or if a new unusual mole appears, especially in adulthood. Prompt evaluation is important because early detection of melanoma greatly improves outcomes. People with many atypical moles or a family history of melanoma should have regular professional skin examinations.
Frequently Asked Questions
Is a dysplastic nevus cancer?
No. A dysplastic nevus is an atypical but non-cancerous mole. However, having atypical moles, especially many of them, is associated with a somewhat higher risk of developing melanoma, so monitoring is important.
Do atypical moles need to be removed?
Most do not need removal and are simply watched over time. A mole is usually removed if it is changing or looks suspicious, in which case it is examined under a microscope to rule out skin cancer.
How can I tell if a mole is dangerous?
The ABCDE rule helps: be concerned about Asymmetry, an irregular Border, varied Color, a Diameter larger than a pencil eraser, and any mole that is Evolving or changing. A mole that itches, bleeds, or does not heal should also be checked promptly.
What causes atypical moles?
They result from a combination of genetics, sun exposure, and skin type. A tendency to have many or atypical moles often runs in families, and ultraviolet light contributes to their formation and to overall skin cancer risk.
How often should I get my moles checked?
People with many atypical moles, a family history of melanoma, or a personal history of skin cancer often benefit from regular skin checks by a dermatologist. Everyone should examine their own skin periodically and report new or changing moles.
References
- National Cancer Institute (NCI). Common moles, dysplastic nevi, and risk of melanoma.
- American Academy of Dermatology. Atypical moles (dysplastic nevi).
- Skin Cancer Foundation. Atypical moles.
- MedlinePlus, U.S. National Library of Medicine. Moles.