[Chondrosarcoma. (An electronmicroscopic study) (author's transl)].

The ultrastructure of 6 chondrosarcomas was analysed. These areas which by means of light microscopy appear benign, displayed the same appearance as chondromas. Malignant areas are characterised by distined variation of cells, nuclei and nucleoli. There is an electron-dense zone of 400 A between the inner membrane of the nucleus and the chromatic in some nuclei containing dense chromatin. The amount of cytoplasmatic organellae decreases as differentiation decreases. Nevertheless there are sometimes cells with an unusual accumulation of cytoplasmic organellae.