Abstract: | 25 synovial sarcomas in patients with various duration of life were studied electron-microscopically. Quantitative correlation between dark and clear tumour cells is the most informative prognostic index in patients operated on because of these sarcomas: the more numerous are dark cells in the tumour, the worse is the prognosis. The appearance of intermediate filaments in the cytoplasm of epithelioid tumour cells and the presence of secretory material in the intercellular spaces are the sign of a less favourable prognosis. |