(Histiocytoma; Benign Fibrous Histiocytoma)

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


A dermatofibroma is an overgrowth of the tissue in the dermis layer of the skin. It is a small, firm bump on the skin. They are harmless and will not turn into skin cancer.

Layers of the Skin

Cut-away of the Skin
In dermatofibroma, the overgrowth occurs in dermis layer of the skin.
Copyright © Nucleus Medical Media, Inc.


The cause is not known. Sometimes they happen after a minor injury to the skin, such as an insect bite or a prick from a thorn.

Risk Factors

They are more common in adults and happen most often in women.


They are most common on the lower legs, but can also appear on the upper arms. They may be:

  • Brown, purple, yellow, red, or pink in color, sometimes with a darker rim
  • Smaller than 1 centimeter
  • Firm
  • Raised from the skin


Your doctor will ask about your symptoms and health history. A physical exam will be done. It will focus on the growth. This may be enough to make the diagnosis.

A growth that cannot be diagnosed may be surgically removed. It will be examined in a lab.


These growths do not go away with time. They also do not need to be treated unless they cause discomfort or are unsightly.

Surgery may be done to remove the growth. This often leaves a scar.

Liquid nitrogen can also be used to freeze the growth and flatten it. This often leaves a white mark. The growth may also come back.


There are no methods to prevent these growths. The cause is not known.


American Academy of Dermatology
British Association of Dermatologists


Canadian Dermatology Association


Common benign skin lesions. EBSCO DynaMed website. Available at: Updated February 5, 2018. Accessed November 21, 2019.
Dermatofibroma. British Association of Dermatologists website. Available at:
...(Click grey area to select URL)
Updated January 2017. Accessed November 21, 2019.
Dermatofibroma. New Zealand Dermatological Society website. Available at:
...(Click grey area to select URL)
Updated January 2016. Accessed November 21, 2019.
Moreno-Ramírez D, Ruiz-Villaverde R, et al. Process of care for patients with benign cysts and tumors: Consensus document of the Andalusian Regional Section of the Spanish Academy of Dermatology and Venereology (AEDV). Actas Dermosifiliogr. 2016 Jun;107(5):391-399.
Last reviewed September 2019 by EBSCO Medical Review Board James P. Cornell, MD
Last Updated: 7/28/2020

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