Dysplastic Nevus
Also known as: Atypical Mole, Clark's Nevus
Atypical moles with irregular features. The single strongest visual risk marker for melanoma.
What to look for
Side-by-side comparison
Common mole
Small, round, even
Dysplastic nevus
Large, irregular, fried-egg shape
A dysplastic nevus is a mole displaying irregular features: larger than 5mm, irregular borders, uneven pigmentation, and often a flat component surrounding a raised center (the fried egg appearance).
Their significance lies in being risk markers for melanoma. Most individual dysplastic nevi will NOT transform into melanoma, but their presence signals increased risk of melanoma developing anywhere on the body. Having 10 or more increases melanoma risk approximately 12-fold.
Patients with dysplastic nevus syndrome (FAMMM) - numerous dysplastic nevi plus family history of melanoma - face lifetime melanoma risks exceeding 50%.
Management is monitoring, not automatic removal. Only nevi showing concerning changes require biopsy. The ugly duckling sign is key: any mole that looks distinctly different from all others deserves attention.
Quick self-check
Does this look like dysplastic nevus? Answer 2 questions.
Is the mole larger than 5mm (pencil eraser size)?
Does it look distinctly different from your other moles?
The ABCDE Rule — Visual Guide
The screening method dermatologists recommend for self-examination.
Asymmetry
One half does not match the other half
Normal
Both halves match
Warning
Halves don't match
Border
Edges are irregular, ragged, or blurred
Normal
Smooth, well-defined edge
Warning
Ragged, blurred edges
Color
Multiple colors or uneven color distribution
Normal
One uniform color
Warning
5+ colors mixed
Diameter
Larger than 6mm — about the size of a pencil eraser
Normal
Under 6mm
Warning
Over 6mm (pencil eraser)
Evolution
Any change in size, shape, color, or symptoms over time
Normal
No change over 12 months
Warning
Grew, darkened, irregular
Most important: Evolution (E) is considered the single most critical criterion. Any mole that is changing — in size, shape, color, or producing new symptoms like itching or bleeding — should be evaluated by a dermatologist regardless of other features. This guide is for screening only.
Risk factors
- Family history of dysplastic nevi or melanoma
- Fair skin (Fitzpatrick I-II)
- Sun exposure and sunburns
- More than 50 total moles
- Personal melanoma history
When to see a dermatologist
- ⚠Any atypical mole actively changing in size, shape, or color
- ⚠A mole that looks markedly different from all others (ugly duckling)
- ⚠If you have many atypical moles - establish baseline photography
- ⚠A dysplastic nevus that bleeds or itches without trauma
Often confused with
Not sure if this is dysplastic nevus? Compare:
Want a more detailed check?
Our full ABCDE checker evaluates 5 clinical criteria in 30 seconds.
Full ABCDE check →Frequently asked questions
Does having atypical moles mean I will get melanoma?
No. Most remain stable. But they are the strongest visual risk marker - indicating higher-than-average risk. More vigilant monitoring is needed, not panic.
Should all dysplastic nevi be removed?
No. Prophylactic removal is not recommended because melanoma can develop from normal skin. The approach is regular monitoring with dermoscopy, removing only those showing suspicious changes.
What is the ugly duckling sign?
Most of your moles look similar. The ugly duckling is any mole that looks clearly different from all others - it deserves evaluation even without obvious ABCDE criteria.
Related conditions
Melanoma
The most dangerous skin cancer - but 99% survival when caught early. Learn the ABCDE signs.
Common Nevus
Normal moles - clusters of pigment cells. Usually harmless, but monthly monitoring for changes is essential.
Spitz Nevus
A dome-shaped pink or brown mole common in children. Can closely resemble melanoma under the microscope - often excised for certainty.