Ecchordosis physaliphora vertebralis.

A microscopic ectopic remnant of notochord and hyaline cartilage was an incidental autopsy finding within a vertebral body. Such ectopic notochordal vestiges have been hypothesized to be the origin of vertebral chordomas, but very few have ever been reported. Whereas ectopic notochord has been demonstrated regularly in the spheno-occipital region (in both embryos and adults) and in the sacrococcygeal region (in embryos), the occurrence of such tissue rests in other segments of the vertebral column is extremely rare. The possible relationship of ectopic vertebral notochordal rests to associated hyaline cartilage formation and to vertebral chordomas requires further investigations.