Dermatofibroma is a firm, red-to-brown, small papule or nodule composed of fibroblastic tissue. It usually occurs on the thighs or legs.

Dermatofibromas are common, more so in women, and typically appear when people are in their 20s. Their cause is unknown. Lesions are usually 0.5 to 1 cm in diameter and feel like a lentil embedded in the skin. Most are asymptomatic, but some itch or ulcerate following minor trauma. Diagnosis is clinical; lesions typically dimple when grasped between the fingers. They may regress spontaneously, but they can be excised if troublesome.

Last full review/revision September 2008 by Daniel W. Collison, MD