Dermatofibroma: A benign skin growth that usually occurs on the legs but may affect the arms or trunk. The growth is usually discolored and contains hard, scar-like tissue. A minor injury such as an insect bite or a thorn can result in a dermatofibroma. The color of the nodule is variable (brown, pink, skin-colored, yellow, purplish).
Melanoma: Serious cancer of the skin (including moles) and sometimes eyes.
Neurofibroma: A benign tumor that originates from nerve cells. The tumors usually arise from nerves in the skin or just under the skin.