Patients with dermatofibroma (DF) present with an asymptomatic smooth, firm, round, brownish papule or nodule, usually measuring less than 1 cm in diameter (Fig. 41-1). There is often a peripheral rim of hyperpigmentation. When DFs are pinched, they dimple in the center. DFs are most commonly found on the legs of women. They are thought to be fibrosing reactions to a local insult such as an arthropod bite or folliculitis.