CT and MRI presentation of intradural epidural angiolipoma of the thoracic spinal canal (with a case report).

Epidural angiolipoma is a rare benign tumor consisting of mature adipocytes, blood sinuses, capillaries, and small blood vessels. It constitutes about 0.04%-1.2% of spinal axis tumors and about 2%-3% of extradural spinal tumors. We report a case of thoracic epidural angiolipoma and review the literature. We describe a 42-year-old woman who had weakness and numbness in her lower extremities prior to diagnosis and had an onset of approximately 10 months. The patient was misdiagnosed as schwannoma on preoperative imaging, possibly because neurogenous tumor is the most common intramedullary subdural tumor, and the lesion grew into bilateral intervertebral foramina. However, the lesion demonstrated high signal on the T2-weighted and T2 fat suppression sequences, and the linear low signal at the lesion edge was ignored, leading to misdiagnosis. The patient underwent posterior thoracic 4-6 laminectomy, pathectomy, and spinal decompression/vertebroplasty under general anesthesia. The final pathologic diagnosis was intradural epidural angiolipoma of the thoracic vertebra. Spinal epidural angiolipoma is a rare benign tumor that occurs frequently in middle-aged women and is mostly located on the dorsal side of the thoracic spinal canal. Magnetic resonance imaging findings of spinal epidural angiolipoma depend on the ratio of fat to blood vessels. Most angiolipomas show equal or high signal on T1-weighted images and high intensity on T2-weighted images, with significant enhancement after injection of gadolinium. The treatment of spinal epidural angiolipoma is complete surgical resection with good prognosis.