- First described in 1924 by Darier and Ferrand
- Intermediate-grade malignancy thought to arise from dermis
- Appears clinically as a nodular cutaneous mass that may, with time, develop satellite nodules or even nodal/visceral metastases
- Histologically similar to solitary fibrous histiocytoma, and can be confused with plexiform neurofibroma
- DFSP distinguished from solitary fibrous histiocytoma by diffuse CD34 positivity, and from plexiform neurofibroma by a complete absence of S100 positivity
- 95% of DFSPs characterized by t(17;22), which fuses PDGF-beta gene to the constitutively active Col1A1 promoter, leading to overproduction of PDGF-beta locally
- Thought to be primarily responsible for observed phenotype
- Primary treatment is wide surgical excision
- Tyrosine kinase inhibitor imatinib active against PDGF-beta receptor-associated tyrosine kinase; has been shown to be effective adjuvant in recurrent disease
- Can dedifferentiate, most commonly into a high-grade fibrosarcoma; secondary fibrosarcoma arising from DFSP typically does not express CD34
- Pigmented variant known as a Bednar tumor
Reference
Enzinger and Weiss's Soft Tissue Tumors. 4th ed. Mosby 2001.
