Giant notochordal hamartoma of intraosseous origin: a newly reported benign entity to be distinguished from chordoma. Report of two cases.

Two cases are reported of a newly described intraosseous entity of vertebral bodies deemed "giant notochordal hamartoma of intraosseous origin". This entity is commonly mistaken for chordoma and must be distinguished from it as the consequences of misinterpretation may be serious. The clinical, radiological and histologic criteria that can be used to distinguish these two entities are emphasized. Included is a proposed pathogenesis for this lesion, its probable notochordal origin, and a review of other probable cases.