ABSTRACT
INTRODUCTION Fibrohistiocytic tumors are a group of soft-tissue neoplasms composed of cells that resemble fibroblasts and/or histiocytes. Historically, fibrohistiocytic tumors were designated as such to imply their tissue origin from a pleuropotential tissue histiocyte that could assume fibroblastic properties. To date, the histogenesis of fibrohistiocytic tumors remains uncertain, although more recent immunohistochemical studies provide evidence that the fibroblast is the probable cell of origin. Despite efforts to reclassify these tumors to correlate with their distinct cell of origin, the term will be used to encompass the three tumors to be discussed in this chapter: dermatofibrosarcoma protuberans (DFSPs), atypical fibroxanthoma (AFX) and malignant fibrous histiocytoma (MFH).
