We experienced 2 cases of lumbar disc herniation extruded to the dorsal epidural space.
Case one; A 51-years-old male developed intense lumbar pain, right lower leg pain and weakness. The lesion appeared as an egg-like filling defect in the L3 body of the vertebra from the border by L4 in myelogram. The lesion occupied a large part of the spinal canal in contrast CT. Lumbar spinal MRI showed iso signal with T1 and low signal with T2.
Case two; A 33-years-old female had developed lumbar and buttock pain. In myelogram, the lesion compressed the epidural space at L5/s1 level from the right. In CT, though the CT number of the lesion was water-density, we had to make the differential diagnosis of the lumbar spinal lesion to be native of hernia. Lumbar spinal MRI showed iso signal with T1, and low and high signal with T2. Two cases were diagnosed with sequestrated hernia in operation findings and pathology findings. It is sometimes difficult to differentiate between hernia to dorsal epidural space and spinal canal inner tumor.
sequestrated hernia changes its brightness grade on MRI with progress. Understanding of the brightness grade on MRI with progress of sequestrated hernia is especially effective to distinguish between the hernia and epidural tumor, and also useful to observe spontaneous resorption of the hernia.