Cytogenetic investigation of chordomas of the skull

We report the first cytogenetic investigation of cranial chordoma. Three cr anial chordomas were examined, two of which could be further histopathologi cally classified as chondroid chordomas. In addition, we have included a ca se of chordoma of a cervical vertebra to compare the cytogenetic abnormalit ies. Diagnosis was made at histological and immunohistochemical levels. The three cases of cranial chordoma showed a normal karyotype, while one verte bra showed 46,XY, t(6;11)(q12;q23). Chordomas, particularly those containin g cartilage, have to be distinguished from chondrosarcomas of the skull bas e. Such a distinction is normally based on expression of epithelial markers which usually are lacking in chondrosarcoma. Cytogenetic investigation may eventually prove to be useful in the distinction of the two lesions, if ch romosome anomalies are consistently absent in chordoma, although some chond rosarcomas may also present a normal karyotype. Such a distinction has clin ical implications because chondroid chordomas show better survival, whereas chondrosarcomas show a propensity to infiltrate the surrounding tissues. ( C) Elsevier Science Inc., 1999. All rights reserved.