Paget disease of the spine manifested by thoracic and lumbar epidural lipomatosis: magnetic resonance imaging findings.

OBJECTIVE: To describe the magnetic resonance imaging (MRI) findings of thoracic and lumbar epidural lipomatosis associated with Paget disease of the spine.

SUMMARY OF BACKGROUND DATA: A 60-year-old male presented with progressive weakness of both limbs and dorsalgia and subsequently developed paraparesis.

METHODS: MRI of the thoracic and lumbar spine were undertaken and urgent decompression laminectomy followed.

RESULTS: MRI of the thoracic spine disclosed abnormal tissue extending posteriorly in the epidural space displacing the spinal cord. The lesion had intermediate to high signal intensity on T1 weighted images and intermediate signal intensity on T2 weighted images. MRI of the lumbar spine revealed abnormal tissue in the extradural space with the same MRI characteristics as seen in the thoracic spine. There was also abnormal signal intensity of the thoracic and lumbar vertebrae at the same levels where the abnormal epidural tissue existed. Abundant infiltrated epidural adipose tissue was removed during urgent decompression laminectomy of the thoracic spine and pathology diagnosed epidural lipomatosis. Histology of the bony elements of the specimen was consistent with Paget disease. Postoperative MRI showed resolution of the epidural mass of the thoracic spine and the patient was discharged 6 weeks after the surgery. Six months later the patient experienced progressively aggravated lumbar pain and sciatica. A follow-up MRI of the lumbar spine showed an increase in the amount of the epidural adipose tissue at this level and more pronounced fatty deposition of the involved lumbar vertebrae. Findings were consistent with progression of Paget disease and lumbar epidural lipomatosis and patient was treated with zoledronic acid. His neurologic function returned to normal within 3 weeks. He is free from symptoms on 5 months follow-up.

CONCLUSION: Paget disease of the spine may rarely be complicated by spinal epidural lipomatosis and may be considered in patients with paraparesis and symptoms of spinal stenosis.