Dermatofibrosarcoma Protuberans (DFSP)

DFSP begins in the deeper layer of the skin as a firm, slowly enlarging plaque or nodule, often on the trunk or shoulders, and often present for years before diagnosis. It rarely spreads to other organs — its danger is local: it sends out root-like extensions well beyond the visible edge of the tumor.

That growth pattern is exactly what margin-controlled surgery exists for. Standard excision judged by eye leaves those roots behind; examining the full margin under the microscope lets the surgeon follow every extension to its end before closing.