Extraskeletal myxoid chondrosarcoma--a clinicopathologic and electron microscopic study.

This clinicopathologic study concerns 14 cases of extraskeletal myxoid chondrosarcoma from among 603 cases of soft tissue sarcomas. The ages of the patients at the time of initial biopsy ranged from 16 to 69 years. The tumors mainly arose in the lower extremities including buttocks (10 cases), and consisted histologically in cords and strands of small acidophilic cells with occasional vacuolated cells in an abundant myxoid matrix composed of chondroitin sulfate. Electron microscopy in four revealed a continuum of cell differentiation of the tumor cells from chondroblastic cell to undifferentiated mesenchymal cell. Morphological studies indicated that the extraskeletal myxoid chondrosarcoma included so-called chordoid sarcoma, as a variant.