[Soft tissue neoplasms--progress and limits of pathologico-anatomic diagnosis]

Current classifications of soft tissue tumors are based principally on the histogenetic type of the tumor thereby abandoning descriptive terms such as spindle cell sarcoma, round cell sarcoma etc. Insight into the histogenesis of a number of soft tissue tumor types has been gained from electron microscopical studies. In addition, these studies provided valuable data to establish certain neoplasms as tumor entities. Thus, the histogenesis of clear cell sarcoma of tendons and aponeuroses has been traced to melanocytes, and it is now universally accepted that biphasic synovial sarcoma consists of epithelial and fibroblastic components. Despite these advances, about 10% of all soft tissue sarcomas remain unclassified when light- and electron microscopy are used in combination. Further improvement in the classification of soft tissue malignancies has been achieved applying immuno-histological techniques. As in other types of malignant tumors mono- and polyclonal antibodies against intermediate filament proteins are especially useful. Other "markers" include protein S-100, neuronspecific enolase (NSE), epithelial membrane antigen (EMA) and panleucocyte antigen (LCA). Regular use of all these markers enabled us to reduce the percentage of unclassified soft tissue sarcomas from 17.6% in the "pre-immune era" to 6.1%.