Epidural Lipomatosis

 T6-T8, dorsal to spinal cord

image Epidural fat ≥ 7 mm thick

• Lumbar spine: 39-42%
image L4-L5, surrounding thecal sac

• Y-shaped configuration to lumbar thecal sac on axial imaging

• Mass effect on thecal sac and nerve roots

• Follows fat signal intensity on all sequences
image Fat suppression to confirm adipose tissue, exclude blood products

Top Differential Diagnoses

• Subacute epidural hematoma

• Spinal angiolipoma

• Epidural metastasis

• Epidural abscess


• Exogenous or endogenous steroids

• General obesity

• Idiopathic

Clinical Issues

• Gradual progression of symptoms

• Weakness: > 85%

• Back pain, sensory loss, polyradiculopathy, altered reflexes, incontinence, ataxia

(Left) Sagittal graphic illustrates confluent abundant epidural fat image in dorsal thoracic canal, with effacement of the dorsal thecal sac and mild mass effect on spinal cord, which is displaced ventrally.

(Right) Sagittal T2WI MR of thoracic spine shows smooth and homogeneous dorsal epidural tissue image, isointense to subcutaneous fat. Vertebral compression fractures are due to steroid-induced osteoporosis.

(Left) Sagittal T1 MR shows abundant epidural fat image both dorsal and ventral to the thecal sac. The thecal sac is small in AP diameter due to compression by the fat.

(Right) Axial T1 MR shows marked prominence of the epidural fat in the lumbar canal, which causes the thecal sac to assume a trefoil pattern. The abundant fat in the epidural space allows for good visualization of the normal anatomy of the Hoffman ligament, which connects the posterior longitudinal ligament to the ventral dura image.



• Excessive accumulation of intraspinal fat causing cord compression and neurologic deficits


General Features

• Best diagnostic clue
image Abundant epidural fat in midthoracic and distal lumbar spinal canal compressing thecal sac

• Location
image Thoracic spine: 58-61%
– T6-T8, dorsal to spinal cord

image Lumbar spine: 39-42%
– L4-L5, surrounding thecal sac

• Size
image Epidural fat ≥ 7 mm thick in thoracic spine

image Over multiple vertebral segments

• Morphology
image Y-shaped configuration to lumbar thecal sac on axial imaging

Radiographic Findings

• Radiography
image Osteopenia from exogenous or endogenous steroids

CT Findings

• Increased fat in spinal canal

• Compression of cord or thecal sac

• No abnormal enhancement

• No bony erosions

Oct 5, 2016 | Posted by in NEUROLOGICAL IMAGING | Comments Off on Epidural Lipomatosis

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