Dermatofibroma (DF) is a common cutaneous nodule of obscure etiology that occurs more often in women. It is also known as a histiocytoma. Dermatofibroma is pronounced as a benign skin growths, found especially on the legs. They can grow up to about 1 cm (less than a half inch) in diameter. The skin escalation is mostly consist of fibrous tissue. They arise as firm-feeling nodules, often yellow-brown in colour, sometimes quite dark, especially in dark coloured skin.

If the skin over a dermatofibroma is squeezed a dimple forms, symptoming tethering of the skin to the underlying fibrous tissue. Typical dermatofibromas cause bit or no discomfort, though itching and tenderness can occur. Dermatofibromas form as a retroaction to previous injuries such as insect bites or thorn pricks.

They are configured of disordered collagen laid down by fibroblasts. DF can happen in patients of any age, but it usually develops in young adulthood. Nearly 20% of the lesions occur before age 17 years. Dermatofibromas have scar tissue and feel like hard lumps in the skin. A minor injury to the skin such as a sting from a thorn, may lead to the dermatofibroma. Dermatofibroma, can be formed by an insect bite.

Treatment of dermatofibromas should be concerned when they get in the way of shaving or become irritated by clothing. Cryosurgery may also be used to remove a dermatofibroma. Other procedures are freezing the lump with liquid nitrogen to flatten it out but this is rarely completely successful and may leave a white mark behind.