Unusual behavior in two cases of chordoma are reported. The first is a sacral primary tumor with widespread metastases. Review of the literature indicates that
[See table in the PDF file]
well documented instances of metastases from these neoplasms are an uncommon occurrence; and that in the majority of cases the sacral area is the primary site. The second report is of a vertebral chordoma that underwent sarcomatous histological transformation three and one-half years after radiation therapy. This is apparently a previously unreported phenomenon.