Seborrhoeic Keratosis or Skin Cancer? How To Tell

Seborrhoeic keratoses are extremely common harmless growths that appear as we age — waxy, warty, brown or black spots that look almost “stuck on” the skin. They are not cancer, and they do not turn into cancer. But because some are dark and irregular, they can be mistaken for melanoma — which is exactly why a spot you are unsure about is worth a doctor’s eye.

Seborrhoeic keratosisA waxy, “stuck-on” brown growth

Clinical image · Wikimedia Commons, CC BY-SA 4.0. Example only — appearances vary; see a doctor for any concerning spot.

What a seborrhoeic keratosis looks like

• Stuck-on, waxy or warty surface, as if it could be scratched off.
• Well-defined edges; brown, tan or black.
• Often several of them, appearing over years on the trunk, face or scalp.
• Usually painless and unchanging.

When to have one checked

The similarity to melanoma is the important part. Get a spot reviewed if it:

• Has uneven colour or an irregular, blurred border.
• Is changing, growing, itching or bleeding.
• Is a new dark spot that stands out from your others (the ugly-duckling sign).

Telling a harmless seborrhoeic keratosis from an early melanoma can be genuinely hard by eye alone — it is exactly the judgement an Australian GP with a special interest in skin cancer medicine using dermoscopy is trained to make.

Not sure? Get it reviewed

Upload a photo and Dr Walia will provide written next-step advice from the submitted photographs, including when an in-person examination is appropriate. Get your spot reviewed — $49. Related: is my mole skin cancer? · milia · about skin cancer.

Not a diagnosis; cannot rule cancer in or out.