Extraskeletal myxoid chondrosarcoma: a histochemical and immunohistochemical study.

In reviewing a large series of soft tissue sarcomas, nine cases of extraskeletal myxoid chondrosarcoma have been retrieved. These tumours, which principally presented in middle-aged adults, have been examined histochemically to determine the heteroglycan content of their myxoid matrix and immunohistochemically for the presence of S-100 protein. The principal mucopolysaccharides identified were chondroitin-4 and 6-sulphate and keratan sulphate; each of the tumours was S-100 positive. The relevance of these findings to the histogenesis and differential diagnosis of these uncommon neoplasms is discussed.