Notochordal inclusions in the vertebral bone marrow.

Nontumoral notochordal inclusions in vertebral bone marrow give rise to MRI-detectable lesion without osteolysis, and their detection may cause concern or overtreatment. These lesions likely arise from dislocation of notochordal cells from the nucleus pulposus early in life, followed by growth in a permissive bone marrow microenvironment. We present a case of nontumoral notochordal inclusions in vertebral bone marrow, giving rise to an MRI detectable lesion without osteolysis. MRI detection of such lesions may cause concern or overtreatment. Quite distinct from chordomas, these lesions likely arise from dislocation of notochordal cells from the nucleus pulposus early in life, followed by growth in a permissive bone marrow microenvironment.