The findings are those of a well differentiated CD34 positive spindle fibroblastic proliferation diagnostic of a dermatofibrosarcoma protuberans (DFSP). Although the architectural growth pattern is fascicular in quality and not significantly storiform, it is not truly a herringbone pattern nor is there enhanced atypia and mitotic activity therefore excluding the possibility of fibrosarcomatous transformation.
DFSP is a locally aggressive sarcoma. While most tumors are low grade, a small fraction contains a higher grade component most commonly in the form of a fibrosarcoma. These tumors rarely metastasize but may recur if inadequately excised.