Syndecan-l expression in different soft tissue tumours

Background: In vitro studies have suggested that expression of syndecan-1 ( CD138) is correlated with morphologic phenotype (epithelioid ol spindle) of cultured tumour cells. Materials and Methods: Fifty-seven different soft t issue tumours were selected to analyse their syndecan-1 (CD138) reactivity. Immunohistochemical staining of paraffin sections, following a high temper ature unmasking technique, was performed The intensity and the pattern of s taining was studied. Results: Cell membrane positivity was observed in epit helioid sa, comas and epithelial elements of synovial sarcomas. GISTs, some malignant epithelioid schwannoma and some fibromatosis showed intracytopla smatic reaction, while pyogenic granuloma, Kaposi's sarcoma, fibrosarcoma a nd dermatofibrosarcoma protuberans were negative. Conclusion: At first it s eemed that the cell membrane positivity of syndecan-1 accompanied true epit helial differentiation in soft tissue sarcomas, but the results further hig hlighted the non specific nature of this expression. Therefore the heteroge neity in the appearance of syndecan-1 in various soft tissue tumours is not simply associated with the phenotype, suggesting more complex functions.