Dermatofibrosarcoma protuberans (DFSP) is a relatively uncommon soft tissue neoplasm with intermediate- to low-grade malignancy. Although metastasis rarely occurs, DFSP is a locally aggressive tumor with a high recurrence rate.
Cultured DFSP tumor cells have increased growth in response to platelet-derived growth factor (PDGF)–beta. Cytogenetic studies may reveal specific lesions in DFSP tumor cells, such as reciprocal translocation of chromosomes 17 and 22, t(17;22), and supernumerary ring chromosomes composed of interspersed sequences from bands 17(17q22) and 22(22q12). These rearrangements fuse the collagen type I alpha 1 (COL1A1) and the PDGF-beta chain (PDGFB, c-sis proto-oncogene) genes. The collagen promoter drives COL1A1 and PDGFB fusion protein production. The fusion protein is then processed into functional PDGF-B and subsequently interacts with the PDGF receptor on the cell surface of DFSP tumor cells. The activation of the PDGF receptor tyrosine kinase triggers the proliferation of DFSP tumor cells. Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive tumor with a high recurrence rate. DFSP is usually not the direct cause of death. The relative 5-year survival rate for DFSP is 99.2%. Although metastasis of DFSP is rare (only 1–4% reported), almost all metastatic cases have been associated with local recurrence and a poor prognosis. Most of the patients with metastatic DFSP have died within 2 years.