A patient undergoes lumbar spine MRI for radiculopathy. The report describes disc material extending beyond the disc space, with its base narrower than the maximal diameter of the extruded fragment. This description is most consistent with which type of disc herniation?

Explanation

According to the updated nomenclature, a disc extrusion is defined as a localized displacement of disc material in which, in at least one plane, the distance between the edges of the disc material beyond the disc space is greater than the distance between the edges of the base of the disc material beyond the disc space. In simpler terms, the neck of the herniation is narrower than the body. A disc protrusion has a base wider than its maximal diameter. A disc sequestration is a type of extrusion where the fragment has lost continuity with the parent disc. A disc bulge is a generalized displacement of disc material.