Chordoma in childhood and adolescence. A clinicopathologic analysis of 12 cases.

Chordoma is a distinctly uncommon neoplasm in the first two decades of life. To characterize further its clinicopathologic features in this age group, we studied 12 chordomas from six males and six females (age range, 1 month to 20 years at diagnosis), with a mean age of 6 years. Six tumors arose in the clivus, four in the cervical or thoracic vertebrae, and two in the lumbar and sacrococcygeal areas. The clinical presentations reflected the location. Histologically, six cases were classic chordomas; the remaining six had atypical or nonclassic features of a round cell or spindle cell tumor. Immunohistochemical stains for vimentin and cytokeratin were positive in all cases tested, whereas epithelial membrane antigen was detected in 11 examples, and S100 protein reactivity was noted in nine lesions. The tumors were uniformly nonreactive for glial fibrillary acidic protein and carcinoembryonic antigen. Electron microscopy in six cases demonstrated large primitive cells with attenuated cell junctions, whorls of cytoplasmic filaments, vacuoles, and glycogen aggregates. Ten children had died of tumor at intervals of 3 weeks to 4.5 years after diagnosis and treatment. Lung, lymph nodes, and other organs were the distant metastatic sites in seven cases. These findings imply that chordomas in children are more variable histologically and may pursue a more aggressive clinical course than their adult counterpart. Immunohistochemical studies are particularly helpful in the differentiation of atypical chordomas from other round and spindle cell neoplasms.