obsolete_chordoma true A malignant tumor arising from the embryonic remains of the notochord. It is also called chordocarcinoma, chordoepithelioma, and notochordoma. (Dorland, 27th ed) A notochordal cancer that derives_from cellular remnants of the notochord. MESH:D002817 James Malone DOID:3302 A malignant bone tumor arising from the remnants of the fetal notochord. Although it can occur at all ages, it is more frequently seen in middle-aged adults. Most frequent sites of involvement are: sacrococcygeal area, spheno-occipital area, and the cervico-thoraco-lumbar spine. Microscopically, chordomas are composed of cells that form cords and lobules, separated by mucoid intercellular tissue. Some of the cells are large (physaliphorous) and have vacuolated cytoplasm and prominent vesicular nuclei. Other tumor cells are small with small nuclei without visible nucleoli. Chordomas tend to recur and may metastasize. The most common sites of metastasis are skin and bone. true SNOMEDCT:50007008 notochordoma 2.32 Chordomas NCIt:C2947 Chordoma (morphologic abnormality) use 'http://www.orpha.net/ORDO/Orphanet_178' instead. New Label : Chordoma http://www.orpha.net/ORDO/Orphanet_178