Remission with Imatinib mesylate treatment in a patient with initially unresectable dermatofibrosarcoma protuberans--a case report.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare, malignant dermal mesenchymal neoplasm characterized by a slow, infiltrative growth. These neoplasms have a high tendency to recur locally after surgical excision. However, metastasizing cases are exceedingly rare. Cytogenetically, DFSP is characterized by a t(17;22)(22;q13) aberration with fusion of the COL1A1 gene on chromosome 17 with the PDGFB gene on chromosome 22. Here, we report on a successful treatment of a patient with a targeted therapy using the tyrosine kinase inhibitor Imatinib mesylate in neoadjuvant intention. PATIENTS AND METHODS: A patient with recurrent and initially unresectable but non-metastatic DFSP of the scalp received Imatinib over 3 months with increasing dosage from 400 mg/day to 800 mg/day orally. Due to the location of the DFSP in our patient, we intended to decrease tumor size preoperatively to allow complete surgical resection. Response to therapy was assessed by computed tomography.
RESULTS: Preoperative treatment with Imatinib resulted in decrease of tumor size by over 60% in the greatest dimension during 3 months of therapy, enabling the complete resection of the DFSP by radical surgery with achieving an acceptable cosmetic result. Surgery was followed by adjuvant Imatinib therapy over 6 months.
CONCLUSIONS: Imatinib mesylate is effective in neoadjuvant treatment of primary unresectable dermatofibrosarcoma protuberans and can be considered as a useful option in the therapy regimen.