dermatofibrosarcoma protuberans /ˌdɜːrmətoʊˌfaɪbroʊsɑːrˈkoʊmə proʊˈtuːbərənz/ noun1 •A rare, slow-growing skin cancer that starts in the deeper layers of the skin. It typically appears as a firm patch or lump and tends to invade nearby tissue locally, but it rarely metastasizes to distant parts of the body.