Dermatofibrosarcoma Protuberans - Fibrosarcomatous Variant

Fibrosarcomatous areas seen in rare cases of DFSP have the following features: they make up at least 5-10% of the overall tumor, have plump spindle cells arranged in fascicles, high nuclear grade, 7-15 mitoses/10 HPF, and reduced/absent staining with CD34. It is not entirely clear whether fibrosarcomatous areas confer a more aggressive behavior on DFSP. With wide local excision, the outcome seems similar to conventional DFSP.