A morphologic study of dermatofibrosarcoma protuberans: expansion of a histologic profile

Dermatofibrosarcoma protuberans (DFSP) is a fibrohistiocytic tumor of intermediate malignancy characterized by a distinctive storiform growth pattern and frequent local recurrences. In this study, we retrospectively reviewed 48 cases of DFSP diagnosed at the Cleveland Clinic Foundation between 1970 and 1999 to determine the prevalence of morphologic variations including the presence of giant cell fibroblastoma (GCF)-like areas, multinucleated giant cells, hypercellular zones and fibrosarcomatous change.

The cohort consisted of 42 patients (20 males, 22 females) with a median age at diagnosis of 40 years (range: 10-73 years). Forty-one primary tumors and seven recurrences were evaluated from these 42 patients. Tumor sites included the trunk (22 cases), head and neck (8 cases), upper extremities (7 cases) and lower extremities (6 cases). GCF-like areas were identified in seven (14.6%), multinucleated giant cells in ten (20.8%), hypercellular zones in 12 (25%) and fibrosarcomatous change in six (12.5%) cases, respectively. Combinations included giant cells and GCF-like areas (two cases), giant cells and hypercellular zone (two cases), and GCF-like areas and hypercellular zones (one case). Our findings suggest that DFSP has a wider range of morphologic features, including GCF-like areas, multinucleated giant cells, hypercellular zones and fibrosarcomatous change, than has been previously recognized in the literature.