Intraosseous benign notochordal cell tumor.

Intraosseous benign notochordal cell tumor is a presumably benign, intravertebral lesion of notochord origin, which can be found incidentally on removal of the vertebra for unrelated lesions or during an autopsy. The notion of a larger benign notochordal cell tumor that is macroscopic, occasionally symptomatic, and seen radiologically was recently introduced, and described as giant vertebral notochordal rest, giant notochordal hamartoma of intraosseous origin, and benign chordoma . Because of the location, size, and similar histologic and immunohistochemical characteristics, larger benign notochordal cell tumors are easily misdiagnosed as the malignant notochord-type of tumor/chordoma, with critical implications. In this review, we attempt to shed light on the major differences between benign notochordal cell tumors and chordoma and other related notochord lesions, such as notochordal vestiges of the intervertebral disk and ecchordosis physaliphora.