[Chordomas]. / Chordomes.

Chordomas are slowly growing malignant tumors arising from notochordal rests. They are occurring in adults (50 to 60 year old) and are mainly (85%) located in sacrococcygeal or spheno-occipital regions; other main localization is cervical spine. Chordomas are usually discovered in patients with pain or symptoms due to compression of surrounding viscera. Radiologically it is characterized by association of osteolysis and soft tissues opacity. On macroscopic examination tumoral tissue has mucoid appearance; under microscope it is made up with lobules of epithelial-appearing cells surrounded by acid mucosubstances. Tumorous cells contain glycogen and neutral mucosubstances. They are surrounded by argyrophilic rim due to pericellular condensation of intercellular matrix, well viewed on electron microscope examination. When their cytoplasm is filled with vacuoles, cells take up typical physaliphorous appearance. Chordomas cells express epithelial differentiation antigens (low molecular weight cytokeratins, EMA, CAM 52, HFM 62, even CEA), Vimentin and S-100 Protein: this triple positivity allow differentiation between chordomas and numerous others tumors. Correct treatment of chordoma is achieved with an initially complete excision. Local recurrences are frequent and sometimes inoperable: in this cases radiotherapy alone may be performed (70 grays). Sarcomas (fibroblastic or Malignant fibrous histiocytoma) may occur after radiotherapy or without it. Hematogenous metastasis occur in 10% to 15% of patients. Survival rate at five years is included between 50% and 75%. Chondroid chordoma is a special entity occurring in younger patients (35 year old) and located in spheno-occipital region. In addition to chordomas it contain chondroid (benign or malignant) islands. Mean survival rate (16 years) is far better than for chordoma or chondrosarcoma.

[Immunohistochemical studies of chordomas and choroid tumors]. / Immunhistochemische Untersuchungen an Chordomen und chondroiden Tumoren.

Chordomas are rare slow-growing but locally invasive tumors. They are thought to develop from residues of the notochord. Three chordomas and ten chondroid tumors were investigated by an indirect immunoperoxidase method for expression of the epithelial markers: MAM-6, keratin, tissue polypeptide antigen (TPA) and for carcinoembryonic antigen (CEA). In all the chordomas investigated the antigens MAM-6, keratin and TPA were detected using monoclonal antibodies and conventional antisera, respectively. These data provide further evidence of the epithelial nature and the ectodermal origin of chordomas. Moreover, the findings suggest that immunohistochemical methods may be useful for the differential diagnosis between chordomas and morphologically similar chondroid tumors.

Sacrococcygeal chordoma: histochemical findings.

Two cases of chordoma of the sacrococcygeal region have been histochemically evaluated. In both cases an irregularly shaped stellate cell, containing large amounts of glycogen, is the prevailing cell type. Neoplastic cells interact with an extracellular matrix consisting of a collagenous framework and a heterogeneous family of glycosaminoglycans with a prevalence of chondroitin sulfate chains and, to a smaller extent, of hyaluronate molecules. We emphasize the value of these data in order to differentiate this tumor from other sacrococcygeal neoplastic lesions.

Type of collagen in chordoma.

Pepsin-soluble collagen was extracted from three histologically proven cases of chordoma and nucleus pulposus. The collagen types of these materials were investigated by differential salting-out, SDS-PAGE (sodium dodecyl sulphate-polyacrylamide gel electrophoresis) of native collagen and their CNBr (cyanogen bromide) cleaved peptides, and their amino acid compositions. Although the collagen of nucleus pulposus was type II, that of chordoma was largely type I. Collagen of notochord, the origin of nucleus pulposus, is known to be type II. Further investigation is necessary in view of the fact that collagen of chordoma, a tumor believed to be derived from notochord, is not type II.

[Electronic microscopic study of a sacral chordoma. Characterization of various development stages of the tumor cells]. / Etude au microscope électronique d'un chordome sacré. Caractérisation de diverses étapes évolutives des cellules tumorales.

The electron microscopic study of a sacral chordoma, the cells of which contain variable amounts of glycogen, allowed to characterize different stages in the evolution of the tumoral cells. The young cells contain almost no glycogen ; progressively it becomes more abundant and fills up almost the whole cytoplasm. At the end of the evolution glycogen disappears while the cell becomes vacuolated. This suggests that enzymatic lysis of this polysaccharide could be the cause of the vacuolation which finally produces the physaliferous cell. Comparison between the cells of the chordoma and those of the normal notochord shows some morphological similarities in the development of these cells. These different data may be useful for a classification of the various types of chordomas.