Doctor performing a pinch test on a dermatofibroma on a patients skin. When a dermatofibroma is squeezed from the sides the overlying skin dimples. This is in contrast to a mole, which stays raised above the skins surface when pinched. 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.