Skin (Melanoma) cancer
A mole that is asymmetric, has an irregular border, uneven color, is large, or is evolving
The five features that separate a benign mole from one that needs a biopsy: Asymmetry (one half doesn’t match the other). Border irregularity (jagged, notched, or blurred edges). Color variation (multiple browns, black, red, white, or blue). Diameter over 6mm (about the size of a pencil eraser). Evolution — any mole that’s changing.
What it could mean
Melanoma is the most dangerous skin cancer, but it’s also one of the most curable when caught early. A mole that meets 2+ ABCDE criteria is a candidate for biopsy. Evolution is the most important. A mole that’s changing is a mole that needs eyes on it, no matter how "normal" it looks.
What it probably is (to be fair)
Most moles are benign. Dysplastic (atypical) moles are common and mostly harmless. But melanomas often start looking like ordinary moles, which is why "watchful waiting" without dermoscopy is a bet, not a plan.
Why this gets dismissed
The words "it looks fine" from a rushed PCP glance are not a skin exam. A real skin check uses dermoscopy (a lit magnifier), takes measurements, and photographs anything suspicious for comparison next year.
If your primary care doctor eyeballed a mole for 5 seconds and said "looks fine," you did not get a skin check. You got a courtesy peek. Ask for a referral to dermatology, or find a dermatology clinic that offers annual full-body skin exams (many charge under $200 without insurance).
When to call your doctor
- Any mole that’s changing in size, color, shape, or symptoms
- A new mole appearing after age 30
- A mole that itches, bleeds, or scabs without healing
- A mole that’s visibly different from your others (the "ugly duckling")
- Any dark spot under a fingernail or toenail (subungual melanoma is often missed)
When to go to the ER
- Skin cancers are not ER situations, but a rapidly growing, bleeding, ulcerated lesion warrants same-week dermatology, not next-month scheduling
If you're dismissed
Ask directly: "Can you use a dermatoscope and photograph this for comparison?" If they can’t, request a dermatology referral. If your insurance requires a referral and your PCP won’t give one, dermatology practices often accept self-referrals for a fee. That’s worth it.
If it runs in your family
A first-degree relative with melanoma triples your risk. Multiple family members with melanoma, pancreatic cancer, or eye melanoma may signal familial atypical multiple mole syndrome (FAMMM). Ask about annual (not periodic) dermatology screening.