IMMUNOHISTOCHEMICAL ANALYSIS OF PLATELET-DERIVED GROWTH-FACTOR AND ITS RECEPTORS IN FIBROHISTIOCYTIC TUMORS

Platelet-derived growth factor (PDGF) is known to stimulate the prolif eration of fibroblasts, although the role of PDGF and its receptors in the development of fibrohistiocytic tumors has not been clarified. In this study, we investigated this role by immunohistochemically staini ng PDGF and PDGF beta-receptors in paraffin-embedded dermatofibroma (D F), dermatofibrosarcoma protuberans (DFSP) and malignant fibrous histi ocytoma (MFH) tissue. We also immunohistochemically investigated the r elationship between PDGF beta-receptors and CD34, which is a known imm unohistochemical marker for DFSP. Immunohistochemical studies using an ti-PDGF-AA or BE antibodies showed that PDGF-AA and BE was found in 20 to 40% of the tumor cells in DF, DFSP, and MFH. No definite relations hip for each tumor type was found. The expression of PDGF beta-recepto rs in DFSP and that of MFH tissue was significantly greater in compari son to DF and scar tissue. The expression of CD34 and PDGF beta-recept ors in DFSP was observed in identical areas. These findings suggest th at autocrine or paracrine growth stimulation, through PDGF beta-recept ors, is related to the tumorous proliferation of fibrohistiocytic tumo rs, and the expression of PDGF beta-receptors might play a role in the proliferation of CD34 positive tumor cells. (C) Munksgaard 1997.