Dermatofibroma: Just Another Brown Bump
Dermatofibroma appears as a firm, dark-brown or red bump on the leg or arm. Dermatofibromas are benign (non-cancerous) skin lesions that are sometimes called a benign fibrous histiocytoma. It is thought that these lesions arise from the site of minor skin injury such as an insect bite or a thorn prick.
Dermatofibromas most often occur on the legs or arms and can persist for years once formed. They can also present as dark brown lesions in persons with darker colored skin. To distinguish a Dermatofibroma from other lesions, you may notice that we squeeze the sides of the lesion. A true Dermatofibroma forms a dimple on the surface when squeezed.
Sometimes, if another type of skin lesion is being considered other than a Dermatofibroma, we may suggest a skin biopsy to determine the origin of the lesion.
A Dermatofibroma is only of cosmetic significance and although it tends to persist long term, it seldom causes any symptoms.
Next time you notice a new red-brown, firm nodule on your arm or leg, squeeze the sides and see if a dimple forms—you may have a Dermatofibroma.