Dermatofibroma Clinical Presentation

Updated: Aug 07, 2020
  • Author: Joseph C Pierson, MD; Chief Editor: Dirk M Elston, MD  more...
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Dermatofibromas typically arise slowly and most often occur as a solitary nodule on an extremity, particularly the lower leg, but any cutaneous site is possible. Dermatofibromas are usually asymptomatic, but itching and pain often are noted. They are the most common of all painful skin tumors. [1] Women who shave their legs may be bothered by the razor traumatizing the lesion in that region, causing pain, bleeding, erosive changes, and ulceration. Although cases of unusually rapid growth exist, most dermatofibromas remain static for decades or persist indefinitely. Patients may describe a hard mole or unusual scar and are often concerned about the possibility of skin cancer.

Several lesions may be present, but rarely are numerous (ie, ≥15) tumors found. This multiple eruptive variant occurs in less than 1% of patients, approximately 60% of whom have an underlying systemic condition, such as HIV infection or systemic lupus erythematosus. [32, 33, 34] However, dermatomyositis, [35] Graves disease, [36] Hashimoto thyroiditis, [37] myasthenia gravis, [37] Down syndrome, [38] leukemia, [39] myelodysplastic syndrome, [40] cutaneous T-cell lymphoma, [41] multiple myeloma, [41] atopic dermatitis, [42] Crohn disease, [43] ulcerative colitis, [44] sarcoidosis, [45] and pregnancy [46] have all been reported in association with the phenomenon. In addition, antiretroviral agents, [47] efalizumab, [48] brentuximab vedotin, [49] antitumor necrosis factor-alpha agents, [50] and the tyrosine kinase inhibitor imatinib [51] have been linked to their appearance.

Both congenital [52] and acquired [53] cases of multiple clustered dermatofibromas have been reported.


Physical Examination

Typically, the clinical appearance of dermatofibroma is a solitary, 0.5- to 1-cm nodule. A sizable minority of patients may have several lesions, but rarely (< 1% of cases) are more than 15 lesions present. (See History) The overlying skin can range from flesh to gray, yellow, orange, pink, red, purple, blue, brown, or black, or a combination of hues (see the image below). On palpation, the hard nodule may feel like a small pebble fixed to the skin surface and is freely movable over the subcutis. Tenderness may be elicited with manipulation of the lesion.

Erythematous, slightly hyperpigmented nodule on th Erythematous, slightly hyperpigmented nodule on the leg. Courtesy of David Barnette, MD.

The characteristic tethering of the overlying epidermis to the underlying lesion with lateral compression (pinching), called the dimple sign, may be a useful clinical sign for diagnosis. [54] However, presence of the dimple sign does not always assure the lesion is dermatofibroma, [55] and dermatoscopy may be useful in supporting the clinical impression. [56]

The extremities are the most common sites of involvement, particularly the legs. [20, 21] Although any cutaneous site can be seen, palm, sole, digital, oral, and genital involvement are relatively rare. Giant [57, 58] (>5 cm in diameter; the largest reported tumor was 17 x 9 x 4 cm [59] ), atrophic, [60] polypoid, [61] and dermatofibroma with spreading satellitosis [62] variants have been reported.

Multiple clustered dermatofibromas [53] are rare and can mimic dermatofibrosarcoma protuberans. This phenomenon has been reported in a segmental distribution. [63]

A halo of dermatitis (Meyerson phenomenon) surrounding a dermatofibroma occurred in one patient. [64]