Dermatofibroma.

Dermatofibroma is a harmless hard nodule that is often found on the legs.

What is a Dermatofibroma?

Dermatofibroma, simply known as DF,  is a common, harmless &  benign growth. Dermatofibroma:

  • Tends to develops between the age of 20 to 50
  • Is more common in women than men.
  • Most commonly occurs on the leg. However, DF can  occur in many different parts of the body.

DF often persists for years. Indeed, DF is commonly seen at a skin check when the typical story is that the person knows they have ‘had it a long time.’

The story goes that DF is a longstanding reaction to an insect bite. The cause of Dermatofibroma is in face unknown. The pathology is that of a benign growth consisting of fibrous tissue which is similar tissue to that that found after an inflammatory reaction.

Dermatofibroma is usually solitary. More than 15 dermatofibromas is described as ‘eruptive dermatofibroma’ and occurs in under 1% of cases. Causes of eruptive DF include immune-mediated diseases.

What does a Dermatofibroma look like?

The lesion projects upwards from the skin surface in the shape of a dome. The colours of dermatofibroma vary. The classical DF has a pink or flesh-coloured centre with a pale brown periphery. Other colours are orange, yellow, red, or sometimes even purple, blue, or black. The size ranges from 3 to 10mm.

When squeezed between the finger and thumb, the hard nodule sinks below the skin (the “dimple sign”). Don’t pinch too deep! Just pinch the surface of the skin skin to feel a very firm lesion.

Which Skin cancers may look like a Dermatofibroma?

Dermatofibroma is usually ‘obvious’ but the following skin cancers may mimic a DF: