Dermatofibrosarcoma protuberans: a clinicopathological study of 20 cases.

Aim: To review the dinical and histological data of 20 cases of dermatofibrosarcoma protuberans presenting at two dermatology centres in Lisbon from 1978 to 1998.

Patients And Methods: The 20 subjects comprised nine males and 11 females ranging in age from 25 to 79 years, with highest frequency of subjects in the 30-50 year olds. We reviewed the clinical features, histopathological aspects, including morphologic variants and immunohistochemical studies.

Results: Median age at diagnosis was 51 years and the trunk was the most frequent location. The characteristic histologic storiform pattern was seen in all cases. Three subjects presented fibrosarcomatous areas, one with myoid differentiation and another with multinucleated giant cells. Immunohistochemical stains revealed CD34 expression in the 18 specimens tested, FXIIIa was negative, and these two antigens proved important for the differential diagnosis of this neoplasm. Local wide excision was performed in 13 cases and seven patients underwent Moh's micrographic surgery. Follow-up ranged from 2 months to 17 years and three recurrences were recorded, two following classical surgery and one after Moh's surgery; there was no difference in the rate of local recurrence (15%) for the two kinds of treatment in our series.