[Malignant neoplasms of the peripheral nerve sheaths with cellular immunophenotype of perineural cells (perineural sarcoma?)].

2 cases of soft tissue malignant tumors formally related to the group of spindle cell sarcoma are described. The majority of cells expressed an epithelial membranous antigen and vimentin but were S-100 protein unreactive, i.e. had a phenotype characteristic of perineural cells. Monoclonal antibodies to 5 types of filaments protein of intermediate type, neurone specific enolase and collagen type I, II, III, IV, V were also used as well as electron microscopic investigation. Problems of differential diagnosis from schwannomas, fibrosarcomas, monophasic spindle cell "synovial sarcoma" and validity of integrating these tumors into an independent variety of malignant peripheral nerve sheath tumors are discussed.