How to Distinguish Dermatofibroma From a Mole

A simple pinch test can tell you if the bump on your skin is benign

A dermatofibroma is a benign skin bump that occurs most commonly on the legs. Dermatofibromas are firm, usually dome-shaped growths that range from brownish to purplish-red in color. They can begin as red and later change to brown. While common on the legs, they can be found throughout the body but especially on exposed parts.

Causes

Dermatofibromas may itch because they're often caused by bug bites. Splinters and minor injuries are common culprits for the appearance of dermatofibromas as well.

Alternate Names

Dermatofibromas are commonly called histiocytomas, but medical professionals use a number of other names for the bumps as well. The following names may be found on a pathology report, but they all refer to dermatofibromas: fibroma simplex, benign fibrous histiocytoma, nodular subepidermal fibrosis, sclerosing hemangioma or dermal dendrocytoma.

Is It a Dermatofibroma or a Mole?

This photo contains content that some people may find graphic or disturbing.

Dermatofibroma
 DermNet / CC BY-NC-ND

Sometimes a dermatofibroma is confused with a mole. The way to tell the difference between the two is to pinch the bump. If you pinch a dermatofibroma, it creates a dimple because it is attached to the underlying subcutaneous tissue. On the other hand, if you pinch a mole, it projects up away from the skin. Moles appear when skin cells grow in clusters.

While dermatofibromas are usually red, brown, or purplish, moles can be tan, black, blue or pink in addition to the typical dermatofibroma's color. Moles can appear in both exposed and unexposed areas of the body, including the armpits or even under nails.

Treatment

Because dermatofibromas are benign (they do not cause cancer) doctors usually do not excise them. In fact, excising the skin growth may produce a scar that's more severe in appearance than the original dermatofibroma. If your physician is unclear about whether you have a dermatofibroma or another type of skin growth, you may have to undergo a biopsy.

A doctor may also recommend treatment for a dermatofibroma if it's in a sensitive area, interferes with your grooming routine, or you experience irritation from wearing clothing as a result of the growth.

Treating a dermatofibroma involves everything from surgical removal of the top of the growth to freezing the top with liquid nitrogen or removing the center. Because these treatments don't completely remove the dermatofibroma, the growths will likely reach their original size again. If that happens, you could have the top removed once more or seek out a procedure to excise the entire growth.

Wrapping Up

If you're unsure whether you have a dermatofibroma, mole or another type of skin growth, consult your physician. Your doctor can evaluate the lump and answer any questions you have about potential problems it can cause or treatment. Remember if your skin growth turns out to be a condition more serious than a dermatofibroma, early detection is key.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. British Association of Dermatologists. Dermatofibroma. Updated January 2017.

  2. Alves JV, Matos DM, Barreiros HF, Bártolo EA. Variants of dermatofibroma--a histopathological study An Bras Dermatol. 2014;89(3):472-7. doi:10.1590/abd1806-4841.20142629

  3. Harvard Health Publishing, Harvard Medical School. Dermatofibroma. January 2019

Additional Reading
  • American College of Osteopathic Dermatology. "Dermatofibroma."
  • Mayo Clinic. "Moles."