(Histiocytoma; Benign Fibrous Histiocytoma)

Pronounced: der-MAH-toe-fie-BRO-ma


A dermatofibroma is a common skin growth. It is a small, firm bump on the skin. The dermis layer of skin contains nerve endings, glands, and vessels. The bump is an overgrowth of the tissue in the dermis layer. The bump is generally pinkish-brown in color. It is often found on the legs. Sometimes more than one appears. Generally, they are harmless and are not connected to skin cancer.

Layers of the Skin
Cut-away of the Skin

In dermatofibroma, the overgrowth occurs in dermis layer of the skin.

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The cause is unknown. Dermatofibromas sometimes appear after a minor injury to the skin. This can include an insect bite or a prick of a thorn.

Risk Factors

Dermatofibromas are more common in women and adults. Childrely rarely have them.


These bumps rarely cause symptoms. However, it is always important to see a doctor about any new skin growth.

Dermatofibromas are:

  • Usually reddish-brown in color
    • Are darker in individuals with darker skin
    • May change color over time
  • Found most often on the legs, but may also appear on the arms or torso of the body
  • Small in size (3-10 millimeters)
  • Very firm to touch
  • Sometimes itchy or sensitive when touched
  • Raised from the skin and may bleed if damaged (a dermatofibroma can bleed if shaven over)


Your doctor will ask about your symptoms and medical history. A physical exam will be done.

A dermatofibroma is diagnosed by sight and touch. Your doctor may also squeeze the skin over the bump. When squeezed together, a dimple will form.

If diagnosis is not certain, the bump can be surgically removed. The removed tissue will be examined under a microscope.


Dermatofibromas do not go away by themselves. Treatment is usually not needed. It may be done if it is causing discomfort (itching or pain) or if they are unsightly. They do not pose any health risk.

Treatment options include the following:


The dermatofibroma may be cut off surgically. This can be done with local anesthesia.

Keep in mind that the dermatofibroma is usually deep. The removal will leave a scar.


Liquid nitrogen can be used to freeze the bump and flatten it out. This method usually leaves a white mark behind. The dermatofibroma may also eventually grow back.


There are no current guidelines to prevent dermatofibromas.


American Academy of Dermatology

British Association of Dermatologists


Canadian Dermatology Association


Common benign skin lesions. EBSCO DynaMed Plus website. Available at: Updated July 24, 2017. Accessed September 1, 2017.

Dermatofibroma. British Association of Dermatologists website. Available at: Accessed September 1, 2017.

Dermatofibroma. New Zealand Dermatological Society website. Available at: Updated January 2016. Accessed September 1, 2017.

Prieto VG, Reed JA, Shea CR. Immunohistochemistry of dermatofibromas and benign fibrous histiocytomas. J Cutan Pathol. 1995;22(4):336-341.

Last reviewed September 2018 by EBSCO Medical Review Board James P. Cornell, MD  Last Updated: 11/16/2012