Dermatofibroma on the arm of an African American female patient. Dermatofibroma, also called benign fibrous histiocytoma, is a non-cancerous tumour that usually occurs on the hands or feet. It is composed of disordered collagen laid down by fibroblast cells. In rare cases, basal cell carcinoma may develop within a dermatofibroma. For a dermatoscope view of this lesion see C057/1907.