DERMATOFIBROMA (ALSO KNOWN AS HISTIOCYTOMA)
What are the aims of this leaflet?
This leaflet has been written to help you understand more about dermatofibromas. It will tell you what they are, what causes them, what can be done about them, and where you can find out more about them.
What is a dermatofibroma?
A dermatofibroma is a common overgrowth of the fibrous tissue situated in the dermis (the deeper of the two main layers of the skin). It is quite harmless and will not turn into a cancer. Another name for dermatofibroma is histiocytoma.
What causes a dermatofibroma to appear?
This is not clear. However they often seem to appear after a minor injury to the skin such as a prick from a thorn or an insect bite.
Are dermatofibromas hereditary?
What are the symptoms of a dermatofibroma?
Usually there are no symptoms but some people may be concerned about how they look. Occasionally they itch or hurt when touched or knocked. If they are on the legs, shaving the skin over them can cause bleeding.
What do dermatofibromas look like?
They are firm bumps that feel like small rubbery buttons lying just under the surface of the skin. They are seldom more than 1 cm across. They lie within the skin and so move with it. A dimple may appear over them when they are pinched.
Their colour ranges from pink to brown.
They can crop up anywhere, but are most common on the lower legs of young or middle-aged adults and on the upper arms of women.
Most people with a dermatofibroma will have only one; some people will have several; this may happen in individuals that have a disease that causes immune suppression (lupus, HIV, some cancers).
Women get them more often than men.
How will it be diagnosed?
A doctor can usually identify a dermatofibroma easily by the way it looks. However, if there is doubt about the diagnosis, or worries over the possibility of skin cancer, the bump can be removed under a local anaesthetic and looked at under the microscope.
Can a dermatofibroma be cured?
Yes, by removal under local anaesthetic with a small margin of surrounding normal skin. This reduces the chance of the dermatofibroma locally recurring.
How can a dermatofibroma be treated?
Dermatofibromas may spontaneously go away, although in many cases they can last indefinitely. However, as they are harmless and cause little trouble, no treatment is usually needed apart from an accurate diagnosis and reassurance.
Dermatofibromas can improve slightly (get flatter) with intra-lesional steroid injections (steroid injections into the lesion).
Cryotherapy (freezing with liquid nitrogen) can be used but it will leave a scar and the lesion may recur.
Some lasers, including carbon dioxide lasers (which work to flatten the lesion) and pulsed dye lasers (which target the blood supply to the lesion) have shown good results but may also scar.
Excision (surgical removal) under local anaesthetic will always leave a scar, which may be as obvious as the original lesion.
Removal of dermatofibromas is often not available in the NHS but may be worthwhile if:
The dermatofibroma is unsightly and you are prepared to swap it for a scar.
It is a nuisance and causing symptoms such as itching or pain – though these symptoms may cease with time and the scar after removal may also be itchy or painful.
There are any doubts about the diagnosis.
What can I do?
Anyone who develops a new lump in their skin, particularly if it is pigmented, should ask their doctor to have a look at it.
Where can I get more information?
Links to other Internet sites:
For details of source materials used please contact the Clinical Standards Unit (firstname.lastname@example.org).
This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists: individual patient circumstances may differ, which might alter both the advice and course of therapy given to you by your doctor.
This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel
BRITISH ASSOCIATION OF DERMATOLOGISTS
PATIENT INFORMATION LEAFLET
PRODUCED DECEMBER 2007
UPDATED DECEMBER 2010, NOVEMBER 2013, JANUARY 2017
REVIEW DATE JANUARY 2020