She undergoes an epidural steroid injection (ESI) after a failed course of physical therapy and antiinflammatory medications. However, the back pain is worsened after the injection and it now is intractable. She is admitted to the hospital for pain management.

• Differential diagnosis includes the following1,2:
  
  
  
  • Congenital: scoliosis with compression of nerve root, short pedicle syndrome
    
  • Infectious: diskitis, osteomyelitis, urinary tract infection, pyelonephritis
    
  • Traumatic: compression or burst fracture (possible with history of minor trauma in elderly patient)
    
  • Tumor: multiple myeloma, bony metastases to the spine, intradural mass
    
  • Endocrine: diabetic neuropathy, other disorders of calcium, paraneoplastic syndrome
    
  • Neural compression: herniated disk, lateral recess stenosis, foraminal stenosis, mechanical instability, spondylolisthesis
    
  • Neuropathic pain
    
  • Degenerative: compression fracture, spondylosis with osteophytes
    
  • Inflammatory: arachnoiditis, perineural fibrosis, ankylosing spondylitis, scar formation
    
  • Vascular: abdominal aortic aneurysm
    
  • Myofascial: injury of musculoligamentous soft tissue structures innervated by the posterior primary ramus of the exiting spinal nerve
    
  • Psychosocioeconomic

• MRI shows an extradural intracanalicular mass at the level of the L2 vertebral body on the left side, extending from L2–L3 disk space to L1–L2 disk space.
  
• The mass is consistent with a large extruded disk fragment likely originated from the L2–L3 disk space and causing severe compression of the left lateral recess and nerve roots.
  
• Other possible but less likely diagnoses include tumor (metastases, schwannoma, meningioma, neurofibroma), abscess, vascular anomaly.

• Given the patient’s age and medical condition, conservative therapy would be the first choice in this case, consisting of^3–5
  
  
  
  • Physical therapy
    
  • Nonsteroidal antiinflammatory medications
    
  • Muscle relaxants
    
  • Other pain medications
    
  • Bracing such as a lumbosacral orthosis

• If physical therapy fails, one may recommend an epidural steroid and analgesic mixture injection at the level of the involved nerve root.⁶
  
• This procedure may require medical clearance and discontinuation of aspirin.

• First, one needs to obtain further investigative studies such as MRI of the lumbar spine and laboratory studies to rule out infection or coagulopathy.
  
  
  
  • Complete blood count; electrolytes; coagulation profile; liver function tests; culture of urine, blood, and sputum; erythrocyte sedimentation rate; C-reactive protein level
  
  
• Depending on the cause, proceed with indicated treatment: evacuation of hematoma or abscess, administration of antibiotics

• There is now an extradural posterior mass at the level of L3–L4, which causes severe compression centrally of the nerve roots and is consistent with either an acute to subacute hematoma or epidural abscess.
  
• The fact that the mass is enhancing on contrast makes it more consistent with an abscess. The previously seen extruded disk fragment is still present.

• Epidural hematoma
  
• Epidural abscess
  
• Both diagnoses are likely linked to the fact that she had an ESI in the face of possibly being immunocompromised from diabetes or old age and coagulopathy from aspirin.^7,8

• She will require evacuation of the extradural mass (and the extruded disk fragment may also be removed in the same sitting).
  
• She will also likely need to be started on intravenous antibiotics, broad spectrum, until final culture results are available (e.g., vancomycin, cefepime, and metronidazole).
  
• Medical clearance needs to be obtained prior to surgery given her age and complicated medical history

• Surgery may consist of a laminectomy from L2–L4 with decompression of the epidural collection.
  
• This will be followed by possible medial facetectomy and resection of the extruded disk fragment at L2–L3.
  
• The epidural collection needs to be sent for culture and Gram stain.
  
• Antibiotics may be withheld until a culture specimen is obtained intraoperatively.
  
• Surgery needs to be done on an urgent basis, within 24 hours (i.e., do not wait one week for effects of aspirin to reverse), but make sure to transfuse platelets preoperatively.