SCLEROSING DERMATOFIBROSARCOMA PROTUBERANS

Dermatofibrosarcoma protuberans is a low-grade sarcoma of the skin wit h well characterized clinical and histopathological features. The lesi on frequently appears as a plaque on the trunk or on the extremities o f middle-aged adults. Microscopically, the tumor is composed of monomo rphous spindle cells arranged in storiform pattern and embedded in a s parse to moderately dense fibrous stroma. We report on two unusual cas es of dermatofibro-sarcoma protuberans in which neoplastic cells were diffusely replaced by sclerotic tissue in more than 50% of the entire tumor in both cases, no external trauma or radiotherapy were recorded. Since tumor regression has been defined as a loss of tumor mass in th e absence of any treatment (or trauma) we believe that sclerosis in DF SP may represent a manifestation of regression and not, as previously suggested, a new variant of the neoplasm.