Dermatofibroma is a common skin lesion which is generally encountered in middle-aged adults and seldomly occur in children. It is suspected that DFs are initiated by injuries to the skin, such as insect bites and trauma. It is possible that after injury the body heals in an abnormal fashion producing DFs. Dermatofibromas occur most commonly on the lower extremities, but may be seen in any location. They usually have no symptoms. Pain and itching may occur occasionally. DF’s are harmless and never turn cancerous, however if diagnosis is uncertain, a biopsy would be recommended.
They are firm, single, elevated dome-shaped bumps that are commonly tan to pink in color. Pinching the lesion gently results in downward movement of the lesion, known as the dimple sign. DFs usually measure from a few millimeters to 10 mm in diameter. Any progressive enlargement beyond 2 or 3 cm suggests a malignant variant and a biopsy is indicated.
DFs are usually asymptomatic and do not require treatment. Treatment would be considered if they get in the way of shaving or get irritated by clothing. DF’s may be biopsied or excised to exclude lesions of malignant origin. Excision for cosmetic purposes leaves scars that are evident and sometimes more noticeable than the original lesion. Another modality used is freezing with liquid nitrogen; however this only treats the upper part of growth and may need repeating. Involution or partial regression may occur after many years if the lesion is left alone.
James W.D., Berger T.G., Elston D.M. Andrews’ Diseases of the Skin. 10th ed. Philadelphia: Elsevier Inc, 2006, p. 611.
Lela Lankerani, D.O.
Department of Dermatology
Philadelphia College of Osteopathic Medicine/Frankford Hospital
Stephen M. Purcell, D.O., F.A.O.C.D.
Professor and Chairman of the Department of Dermatology
Philadelphia College of Osteopathic Medicine