Monophasic synovial sarcoma, epithelioid sarcoma and chordoid sarcoma: ultrastructural evidence for a common histogenesis, despite light microscopic diversity
Cooney, T.P.; Hwang, W.S.; Robertson, D.I.; Hoogstraten, J.
Histopathology 6(2): 163-190
ISSN/ISBN: 0309-0167 PMID: 6281155 DOI: 10.1111/j.1365-2559.1982.tb02713.x
Ultrastructural examination of 6 rare sarcomas.sbd.4 monophasic spindle cell tumors, 1 epithelioid sarcoma and 1 chordoid sarcoma.sbd.revealed marked similarities at the EM level despite widely divergent light microscopic appearances. These features consisted of the presence of 2 cell types (a clear cell and a cell resembling the fibroblast), pseudoglandular spaces with projecting microvilli or filopodia and with related tight junctions and an amorphous intercellular ground substance with focal condensation into recognizable basement membrane. The findings suggest a common maturation of these diverse tumors to synovial-like tissue and support the proposal that these be considered variants of synovial sarcoma. Published ultrastructural studies of synovial, epithelioid and chordoid sarcoma are reviewed in the light of these findings. The ultrastructural differentiation of synovial sarcoma from extraskeletal myxoid chondrosarcoma, chordoma and the spectrum of malignant spindle cell tumors is discussed.