Soft Tissue, Extraskeletal myxoid chondrosarcoma

Extraskeletal myxoid chondrosarcoma is a malignant tumour that resembles cartilage, but is of uncertain differentiation. This slide is from a core biopsy. Nevertheless, it illustrates well the main features of multinodularity, abundant myxoid matrix, and small chondroblast-like cells arranged in loose cords. The chondroid matrix can be further highlighted using a toluidine blue stain. The tumour cells are S100 and vimentin positive, keratin negative. Around half of cases demonstrate rearragment of the EWS gene.