The surgical pathology of notochordal remnants in adult intervertebral disks: a report of 3 cases.

The notochord plays a critical role in organizing and directing vertebral development. In humans, most notochordal cells are eventually sequestered into the nucleus pulposus and disappear within the first decade of life. Although notochordal remnants and related lesions have been described in the axial skeleton of adults, their presence in intervertebral disks is rare. We describe herein 3 cases of incidental notochordal remnants identified in surgically removed adult intervertebral disks. Their histologic features were reminiscent of notochordal vestiges in the fetus. However, they raised the differential diagnosis of benign notochordal cell tumor and chordoma. Notochordal rests can be a source of diagnostic confusion and should be distinguished from notochordal neoplasms because they do not necessitate resection or other forms of therapy.