(Histiocytoma; Benign Fibrous Histiocytoma)
A dermatofibroma is extremely common. It is a small, firm bump on the skin. The bump is an overgrowth of the tissue lying between the outer and inner layers of skin. The bump is generally pinkish-brown in color and is often found on the legs. The dermatofibroma usually occurs alone and has no symptoms at all. Sometimes more than one appears. Generally, they are harmless and have no connection to skin cancer.
Layers of the Skin
The cause is unknown. They sometimes seem to appear after a minor injury to the skin. This can include an insect bite or a prick of a thorn.
The following factors increase your chance of developing dermatofibromas:
- Sex: women are more likely to develop this condition than men.
- Age: middle-aged adults (dermatofibromas are rarely found in children)
These bumps rarely cause symptoms. However, it is always important to see a doctor about any new skin growth.
Usually reddish-brown in color
- Darker for individuals with darker skin
- Color may change over time
- Found most often on the legs, but may also appear on the arms or trunk of the body
- Small in size (3-10 millimeters)
- Very firm to touch
- Occasionally itchy or sensitive when touched
- Raised from the skin and may bleed if damaged (For example, if you shave over a dermatofibroma, it can bleed)
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 there is doubt, the bump can be surgically removed. The removed tissue is then examined more thoroughly under a microscope.
Dermatofibromas do not go away by themselves. However, treatment is usually not necessary. It may be done if they are causing you some discomfort (itching or pain) or you feel they are unattractive. They do not pose any risk to your health.
Talk with your doctor about the best plan for you. 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 always leave a scar. The scar may not be any more attractive than the dermatofibroma itself.
Liquid nitrogen can be used to freeze the bump and flatten it out. This method usually leaves a white mark behind. Also, the dermatofibroma may eventually grow back.
American Academy of Dermatology
British Association of Dermatologists
Canadian Dermatology Association
Dermatofibroma. Beers MH, Berkow R, eds, The Merck Manual of Diagnosis and Therapy, Section 10, Chapter 125, Benign Tumors. The Merck Manual website. Available at: http://www.merck.com/mrkshared/mmanual/section10/chapter125/125i.jsp . Accessed September 12, 2005.
Dermatofibroma. British Association of Dermatologists website. Available at: http://www.bad.org.uk/patients/leaflets/fibroma.asp . Accessed September 12, 2005.
Dermatofibroma. New Zealand Dermatological Society website. Available at: http://dermnetnz.org/lesions/dermatofibroma.html . Accessed September 12, 2005.
Prieto VG, Reed JA, Shea CR. Immunohistochemistry of dermatofibromas and benign fibrous histiocytomas. J Cutan Pathol . 1995;22(4):336-341.
Last reviewed January 2009 by ]]>Ross Zeltser, MD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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