We all have skin spots that seem to appear out of nowhere—tiny freckles from sun exposure, long-standing moles we barely notice, and the occasional weird new mark that sets off alarm bells. Most moles are harmless. But some spots can signal skin cancer, including melanoma, which is dangerous if missed. The trick is knowing what’s normal for you and what deserves a professional look.
Start with the ABCDEs of Melanoma
Dermatologists often teach the ABCDE rule to flag suspicious features:
-
A—Asymmetry: One half doesn’t match the other.
-
B—Border: Edges are irregular, scalloped, or blurred.
-
C—Color: Multiple colors (tan, brown, black, red, white, blue) or an uneven shade.
-
D—Diameter: Larger than a pencil eraser (about 6 mm). Small melanomas exist, so don’t ignore smaller spots with other warning signs.
-
E—Evolving: Any change—size, shape, color, elevation—or new symptoms like itch, tenderness, bleeding, or crusting.
If a spot ticks any of these boxes, schedule a skin check.
The “Ugly Duckling” Sign
Your moles tend to share a family resemblance. The one that looks different—the “ugly duckling”—is the one to show your dermatologist. Maybe it’s much darker, much lighter, growing faster, or just doesn’t match your usual pattern.
Common Benign Look-Alikes
-
Typical moles (nevi): Usually uniform in color, round/oval, and stable over time.
-
Seborrheic keratoses: Waxy, “stuck-on” growths that can crumble if picked; benign but can mimic melanoma.
-
Cherry angiomas: Bright red dome-shaped dots from blood vessels; harmless.
-
Lentigines (sun spots): Flat brown spots from sun exposure, with even color and crisp borders.
Even benign lesions can be confusing. When in doubt, get it checked—no shame in a “better safe than sorry” visit.
Risk Factors That Raise the Stakes
You should be extra vigilant if you have: a history of melanoma or other skin cancers; many or atypical moles; fair skin that burns easily; blistering sunburns; tanning bed use; a family history of melanoma; or a weakened immune system. People of every skin tone can develop skin cancer, but it may be diagnosed later in darker skin because it’s harder to spot—check palms, soles, nails, and lighter areas like scars.
What to Expect at the Dermatologist
A skin exam is quick and usually painless. The clinician may use a dermatoscope—a special lighted magnifier—to evaluate structures beneath the surface. If something looks suspicious, they’ll perform a biopsy (a small sample under local anesthesia). Biopsy is the only definitive way to diagnose cancer. If malignant, most early melanomas are highly curable with prompt excision.
Smart Self-Care Between Visits
-
Do monthly self-checks: Use good light and mirrors; photograph moles to track changes.
-
Protect your skin: Broad-spectrum SPF 30+, reapply every two hours outdoors; hats, sunglasses, shade; avoid tanning beds.
-
Mind changes: Itching, bleeding, scabbing, rapid growth, or a new pigmented streak in a nail—get those evaluated.
Bottom Line
You don’t need to panic over every spot—but don’t ignore changes either. Use the ABCDEs, the ugly-duckling rule, and your intuition. If something looks new, different, or evolving, book a professional skin exam. Catching skin cancer early can be life-saving, and getting reassurance when it’s benign is worth the peace of mind.