[Desmoid tumor - transformation into fibrosarcoma (author's transl)].

Report of a case of aggressive musculo-aponeurotic fibromatosis in a 14-year-old girl with transformation into fibrosarcoma, 10 years later. The tumoral mass initiated its growth in the nuchal region but finally invaded both the cervical and the right retroscapular region. Evidence for muscular, osseous and neurological invasion and destruction was found. The tumor could be controlled neither by surgery, nor by radiotherapy and chemotherapy. This case report is studied in the light of cases reported in the literature.