Dermatofibroma

Histiocytoma, dermatofibroma lenticulare, fibroma en pastille, hard fibroma, Subepidermal nodular fibrosis, Sclerosing angioma

Dermatofibroma is a benign dermal and superficial subcutaneous proliferation. It is made up of  oval cells which resemble histiocytes, and spindle‐shaped cells resembling fibroblasts and myofibroblasts.

More common in women in young adulthood.

• Trigger:
  • Ictus reaction
  • Folliculitis
  • Ruptured cyst
  • Microtrauma

This is followed by an inflammatory reaction of the connective tissue.

Mostly appears on the lower extremity as a red/brown, sharply defined, lenticular nodule is visible.

If the skin lesion is fixed between thumb and index finger, the nodule sinks (Fitzpatrick sign).

In the case of unusually large dermatofibromas (> 5 cm diameter) one speaks of giant dermatofibromas.

• Clinical features
• Biopsy if uncertain.

Taking medication.

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4. Abenoza P, Lillemoe T. CD34 and Factor XIII a in the Differential Diagnosis of Dermatofibroma and Dermatofibrosarcoma Protuberans. The American Journal of Dermatopathology 1993;15:429-34.
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