ABCDE
Melanoma Warning Signs
Five features that turn a mole into a biopsy referral.
Memory aids matter when you have eight minutes with a patient and three new moles to triage. ABCDE — Asymmetry, Border irregularity, Color variation, Diameter over 6 mm, Evolution — is the screening shorthand every primary care NP runs in their head during a skin check. Evolution is the highest-yield letter; a changing lesion outweighs a stable one even with one or two other features. The AANP exam uses ABCDE as a distractor-killer in dermatology vignettes where one option is reassurance, one is a recheck, and one is a referral for biopsy. Pick referral whenever two letters are clearly positive.
- AAsymmetryOne half of the lesion does not match the other.
- BBorderIrregular, ragged, notched, or blurred edges.
- CColorVariegation — shades of black, brown, tan, red, or white within one lesion.
- DDiameter>6 mm (pencil-eraser size), though melanomas can be smaller.
- EEvolvingAny change in size, shape, color, or new symptoms (itch, bleed).
Clinical Context
Screening mnemonic for suspicious pigmented lesions. Any positive feature warrants dermatology referral for biopsy (excisional preferred when feasible). Evolving (E) is often the single most sensitive feature — the history "my mole has changed" carries real diagnostic weight.
Melanomas don't always meet all five criteria — amelanotic melanoma may lack color variation, and some nodular melanomas are small at diagnosis. The "ugly duckling" sign (one lesion that stands out from the patient's other moles) complements ABCDE. AANP primary-care questions test this as part of skin assessment and cancer screening.
Sources
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