Spinal hamartoma associated with spinal dysraphism.

OBJECTS: The aims of the study were (1) to review the pathological findings of spinal lipomatous masses associated with congenital spinal dysraphism and (2) to discuss the pathological diagnosis.
METHODS: The pathological records of 47 patients at our institution were reviewed, and three illustrative cases were presented.
CONCLUSION: Spinal tumorous lesions associated with spinal dysraphism have been traditionally described as lipoma since they are composed mostly of fatty tissue. However, they are different from lipomas arising in other part of the body in that they often contain various tissues of ecto- and mesodermal origin. In our study, we detected such heterotopic components in 24 out of 47 cases. Although they are also similar to teratoma, it is generally accepted that they are malformative lesions which lack neoplastic potential. We therefore should diagnose them as hamartoma rather than lipoma or teratoma.