Immunohistochemical analysis of platelet‐derived growth factor and its receptors in fibrohistiocytic tumors

Platelet-derived growth factor (PDGF) is known to stimulate the proliferation 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 staining PDGF and PDGF β-receptors in paraffin-embedded dermatofibroma (DF), dermatofibrosarcoma protuberans (DFSP) and malignant fibrous histiocytoma (MFH) tissue. We also immunohistochemically investigated the relationship between PDGF β-receptors and CD34, which is a known immunohistochemical marker for DFSP. Immunohistochemical studies using anti-PDGF-AA or BB antibodies showed that PDGF-AA and BB was found in 20 to 40% of the tumor cells in DF, DFSP, and MFH. No definite relationship for each tumor type was found. The expression of PDGF β-receptors in DFSP and that of MFH tissue was significantly greater in comparison to DF and scar tissue. The expression of CD34 and PDGF β-receptors in DFSP was observed in identical areas. These findings suggest that autocrine or paracrine growth stimulation, through PDGF β-receptors, is related to the tumorous proliferation of fibrohistiocytic tumors, and the expression of PDGF β-receptors might play a role in the proliferation of CD34 positive tumor cells.