This study is aimed to investigate the efficacy of imatinib (Glivec) in the treatment of primary and locally relapsed dermatofibrosarcoma protuberans (DFSP). DFSP is a cutaneous neoplasm well known for its overexpression of the platelet-derived growth factor (PDGF). Herein, imatinib provides a systemic treatment option that offers the possibility of a reduction of the wide surgical margins used today in surgery of primary DFSP, or even of a complete avoidance of surgical treatment in this disease. Since imatinib exerts its function via interference with protein tyrosine kinase activities, it inhibits the platelet-derived growth factor receptor (PDGF-R) signaling cascade that plays a crucial role in the pathogenesis and tumor growth of DFSP. Since imatinib has been shown to shrink metastatic lesions of DFSP, there is a strong rationale to expect that it also decreases cell proliferation and tumor growth in primary DFSP.