Pediatric dermatofibrosarcoma protuberans in Madrid, Spain: multi-institutional outcomes.

Little is known about the incidence and management of dermatofibrosarcoma protuberans (DFSP) in children. We conducted a retrospective review of all patients younger than 18 years of age treated for DFSP over a period of 11 years (2000-2011) in Madrid, Spain. The sample consisted of 13 children. The average annual incidence of DFSP in the pediatric population corresponded to 1.02 cases per million person-years (95% confidence interval 0.55, 1.73). Sites of involvement were diverse, with 15.3% of tumors found in acral locations. The median tumor size was 3.5 cm × 3 cm and the median time from apparent onset to diagnosis was 36 months. Histopathologic examination revealed conventional (77.0%), pigmented (15.4%), and myxoid (7.6%) variants. The mitotic index was consistently <5 per 10 high-power fields. All lesions were removed using surgical excision. One patient developed a local recurrence because of initial affected margins; none developed metastases. The median duration of clinical follow-up was 70.5 months. This study estimated the average annual incidence rate of DFSP in a population of patients younger than 18 years and reviewed the experience of several hospitals in the management of this tumor.