Dermatofibroma
Sclerosing angioma, Histiocytoma
A typical dermatofibroma
Features
Dermatofibroma is defined as a nodular dermal proliferation. On examination, it is a firm, elevated or flat, generally hyperchromic, tender nodule which dimples when the overlying dermis is squeezed, indicating tethering to the underlying lesion. The yellow-brown colour of the nodule is due to iron and melanin deposition, sometimes causing diagnostic confusion.
Dermatofibromas arise relatively quickly and are most often found singularly on the limbs, although they may occur in groups. Occassionally, giant lesions (over 5cm) are seen, although they normally range from several millimeters to 1-2cm.
Incidence
Dermatofibroma is a lesion frequently found in dermatological practices. They are more common in young women.
Aetiology
An abnormal response to dermal injury (such as insect bites) is thought to give rise to the lesion, although this is still a contentious issue.
Differential Diagnosis
Dermatofibrosarcoma protuberans. Naevi. Nodular melanoma.
Treatment
The lesions are benign and stable, so no treatment is required. However, intralesional steroids have been shown to initiate regression. If suspicious of a melanocytic lesion, excision biobsy is indicated.
