Dermatofibrosarcoma protuberans (DFSP) is a rare type of skin cancer. It starts in connective tissue cells in the middle layer of the skin (dermis).
Dermatofibrosarcoma protuberans might look like a pimple or feel like a rough patch of skin at first. As it grows, lumps of tissue (protuberans) may form near the surface of the skin. This skin cancer often forms on the arms, legs and trunk.
Dermatofibrosarcoma protuberans grows slowly and rarely spreads beyond the skin.