Written & reviewed by Dr Rupinder Singh Walia — MBBS, FRACGP, Dip. Dermatology (Cardiff, UK) · AHPRA MED0001647256 · special interest in skin cancer medicine & dermoscopy
The signs that mean “get it checked”
New
a new, unusual spot
Changing
size, shape or colour
Growing
getting bigger
Bleeding
or crusting, or itching
Won’t heal
a sore that keeps returning
Any one of these is worth a doctor’s eye — skin cancer is often painless early on.
Dermatofibromas are harmless firm nodules in the skin — small, often brownish, and most common on the legs and arms, frequently after a minor injury or insect bite. They are not cancer. Knowing them is useful so you can tell them from a lump that does need a doctor’s eye.
DermatofibromaA firm, dome-shaped nodule (dimples inward when pinched)
Clinical image · dermatology atlas via the Fitzpatrick 17k dataset, used for education. Example only — appearances vary; see a doctor for any concerning spot.
What a dermatofibroma looks like
Firm and small (often 5–10 mm), sitting in the skin.
Skin-coloured to brown or pink.
The “dimple sign” — it dimples inward when pinched from the sides.
Most skin-cancer advice tells you to watch for change. Skin360AI helps you keep photos of one or more spots connected over time. A spot can be a mole, freckle, mark, lump, sore, patch or any skin area you want to watch. It is not a diagnosis and cannot rule skin cancer in or out.
Check and watch the spots you care about over time
Use the free AI-assisted skin check to save photos of moles, marks, lumps, sores, patches or other skin areas you want to watch. A photo record is not a diagnosis or a cancer all-clear.
A structured photo record is not a diagnosis, cannot exclude skin cancer and does not replace an in-person examination.
Medically reviewed by Dr Rupinder Singh Walia (MBBS, FRACGP, Diploma in Dermatology — Cardiff University, UK; AHPRA MED0001647256). Last reviewed August 2026. This information is general and is not a diagnosis; it cannot rule skin cancer in or out. See your GP or a skin-cancer clinic in person for anything that concerns you.
DermatofibromaA firm, dome-shaped nodule (dimples inward when pinched)