How to Distinguish Dermatofibroma From a Mole

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. (In light-skinnned people, they are typically pink to light brown; in dark-skinned people, they are dark brown or black.) 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, like the arms and the upper back.

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. As the growths mostly appear in adults, age may be another risk factor. People who have suppressed immune systems may also have multiple dermatofibromas.

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?

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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) healthcare providers 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 healthcare provider is unclear about whether you have a dermatofibroma or another type of skin growth, you may have to undergo a biopsy.

A healthcare provider may also recommend treatment for a dermatofibroma if it's in a sensitive area, interferes with your grooming routine, or you experience irritation or itching 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 healthcare provider. They can evaluate the lump and answer any questions you have about potential problems it can cause or treatment.

Be sure to report any growth that bleeds, becomes painful, itches, or grows rapidly as soon as possible. In some cases, such growths can be a sign of more serious skin conditions. If your skin growth turns out to be a condition more serious than a dermatofibroma, early detection is key.