Chronic spontaneous lumbar epidural hematoma simulating extradural spinal tumor: a case report.

Spinal epidural hematoma (SEH) is an uncommon disorder, and chronic SEHs are rarer than acute SEHs. However, there is few reported involving the bone change of the vertebral body in chronic SEHs. We present a case report of lumbar epidural hematoma that required differentiation from extramedullary spinal tumors by a long process because the CT scan revealed scalloping of the vertebral body and review the relevant literature. A 78-year-old man had experienced a gradual onset of low back pain and excruciating pain in both legs. Lumbar MRI on T1-weighted images revealed a space-occupying lesion with a hyperintense signal relative to the spinal cord with no enhancement on gadolinium adminisration. Meanwhile, T2-weighted images revealed a heterogeneous intensity change, accompanying a central area of hyperintense signals with a hypointense peripheral border at the L4 vertebra. Moreover, the CT scan demonstrated scalloping of the posterior wall of the L4 vertebral body which is generally suspected as the CT finding of spainal tumor. During the epidural space exploration, we found a dark red-colored mass surrounded by a capsular layer, which was fibrous and adhered to the flavum and dura mater. Microscopic histological examination of the resected mass revealed a mixture of the relatively new hematoma and the hematoma that was moving into the connective tissue. Accordingly, the hematoma was diagnosed as chronic SEH. The particular MRI findings of chronic SEHs are helpful for making accurate preoperative diagnoses of this pathology.