Dermatofibroma Physical Examination
The lesion is fixed within the skin, but movable over the underlying subcutaneous fat. On palpation, the lesion feels like a firm button. Pinching a dome-shaped dermatofibroma between two fingers causes the lesion to retract and dimple below the level of surrounding skin.
Rarely, lesions may be blue to black in color as a result of hemosiderin deposition, which may resemble melanoma. The surface may be smooth and shiny to scaly or excoriated.
Although dermatofibromas may arise on any cutaneous surface, most are found randomly distributed on the extremities. Lesions are usually solitary, however, multiple lesions are not uncommon. Rarely, dermatofibromas occur on the palms or the soles. Dermatofibromas should be stable in size, appearance, and color.