[Diagnosis of epithelioid sarcoma]

Epithelioid sarcoma is a rare soft tissue tumour. Small-nodular structure, necrotic foci in the centre of tumour nodes, moderate lymphocytic infiltration are characteristic histologic features of this tumour. Majority of tumour cells have the appearance of epithelioid histiocytes. Some tumour cells are found in small cavities resembling hyalin cartilage lacunes. Signs of a synovial, fibroblastic and histiocytic differentiation are observed ultrastructurally in the epithelioid sarcoma cells On the basis of the literature analysis and their own ultrastructural data the authors conclude that there should be a relation of this tumor with pluripotential stem cells of mesenchyma surrounding distal part of the chondral bone germ.