Spontaneous regression of a huge subligamentous extruded disc herniation: short report of an illustrative case.

Herniated nucleus pulposus (HNP) is a common cause of radicular and low-back pain. Although some patients need surgical intervention because of prolonged intolerable leg pain, the majority heal with conservative treatment. Recently, with the advent of imaging diagnostic methods, there is an increasing interest in the phenomenon of spontaneous resorption of the HNP. We presented a case of lumbar HNP at the L4-L5 level in which clinical improvement was associated with a significant decrease in size of a huge subligamentous extruded disc herniation, documented on serial magnetic resonance imaging (MRI) scans.