DERMATOFIBROSARCOMA PROTUBERANS WITH FIBROSARCOMATOUS AREAS - A CLINICOPATHOLOGICAL AND IMMUNOHISTOCHEMICAL STUDY IN 4 CASES

Dermatofibrosarcoma protuberans (DFSP) with fibrosarcoma (FS)-like are as (DFSP-FS) is a peculiar neoplasm that combines microscopic findings of DFSP and FS. Because of the scarce number of cases published, tumo r prognosis remains controversial. The clinical histories and the hist ologic material of 27 cases of DFSP were reviewed. Four of them showed fibrosarcomatous areas. Follow-up data, ranging from 12 to 125 months , were obtained in all four cases. Two patients had repeated local rec urrences. One patient developed pulmonary metastases and died of disea se 49 months after diagnosis. In the other two patients, no recurrence s or metastases were detected at 12 and 70 months after local excision , respectively. Progressive increase of FS areas, cellular density, ce llular atypia, and mitotic activity were observed during the recurrenc es. All cases showed diffuse positive immunostaining for CD34 in DFSP areas. Three cases were also CD34-positive in FS areas. Based on a car eful review of the literature and our personal experience, we conclude that DFSP-FS is a rare variant of DFSP with a higher rate of local re currences and more distant metastases than typical DFSP.