Dermatofibrosarcoma Protuberans

Definition

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 translocationof 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...